Chapters 00.   Introduction 01. Executive Summary 02. A quick overview of Wi-Fi 03. ★Wi-Fi's weak link: your client 04. ★Client 'PHY' speed is key 05. Understanding Wi-Fi Overhead 06. Router Marketing Hype 07. MIMO - a wireless revolution 08. Wi-Fi 1/2/3 - legacy 802.11 09. Wi-Fi 4 - 802.11n (HT) 10. Wi-Fi 5 - 802.11ac (VHT) 11. Wi-Fi 6 - 802.11ax (HE) 12. Wi-Fi 6E - 802.11ax in 6 GHz 13. Wi-Fi 7 - 802.11be (EHT) 14. DFS channels in 5 GHz 15. Router/Wi-Fi setup tips 16. ★How to improve Wi-Fi speeds 17. Wi-Fi Range Extenders 18. Wireless Access Points 19. Mesh Wi-Fi Networks 20. A Reality Check 21. ★Recommendations 22. Wrapping it all up Extras E1.   Ethernet / PoE E2. BufferBloat E3. New home construction tips E4. The cost of 'always on' E5. MoCA - Ethernet over Coax E6. Wi-is-Fi Windows Tools E7. Recommended Cable Modem E8. Powerline Networking / PLC E9. POTS (Telephone) to Ethernet

Appendices A.   Troubleshooting B. Router Specifications C. Netgear 'Mode' D. Throughput testing E. PHY is asymmetric F. PHY speed tables G. mW, dBm, dB H. Maximizing Wi-Fi range I. Signal vs distance J. Channel width vs range K. SINR / SNR / Noise floor L. Router Deep Dive M. WiGig - 802.11ad N. Beware tri-band hype O. Extending to Outbuilding P. Router/AP Placement Q. What 'Stream' means R. Learn more S. Spectral Masks T. Terminology V. Version history W. Call for changes / rants X. Supporting wiisfi.com Y. Contact the author

Faster navigation TIP: As you scroll through this paper, headers are 'sticky' and remain docked at the top of the web browser window. Clicking anywhere on a header takes you back to the top of this paper.

1.95 Gbps real throughput -- Intel AX210 client to TP-Link AX80 (2402 PHY -- 5 GHz band 160 MHz channel 114)

TP-Link Archer AX80

And now the next generation Wi-Fi 7 [§13] is just starting to trickle out.

The dirty little secret in the router industry is that virtually ALL routers (of the same Wi-Fi generation) have the SAME maximum PHY speed to YOUR 2×2 MIMO client device. And likely very similar throughput speeds when standing right next to the router. So the real differentiator is how the router performs 'at distance' for your devices (DFS, MIMO, etc), at your location (contention, interference, etc).

For Wi-Fi 6 client devices, throughput can be around 1 Gbps 1201 Mbps PHY speed for an 80 MHz channel, provided your 2×2 client device is very close to the router, and even faster speeds (and an extended range for obtaining 1 Gbps) are possible with 160 MHz channels.

Fundamental theorem of Wi-Fi: Wi-Fi speed decreases very quickly as 'distance from the router' increases.

Other examples of brand names (mentalfloss.com) now used by most as 'generic terms' due to wildly successful branding (eg: Jet Ski, Jacuzzi, Kleenex, etc).

Typical Wi-Fi 'client device' maximum throughput¹
Version	Sym	Bits	QAM	Enc	MIMO	MHz	PHY	Mbps
Wi-Fi 1 802.11	11.0	2	-	1/11	-	22	2	1
Wi-Fi 2 802.11b	11.0	8	-	1/8	-	22	11	5
Wi-Fi 3 802.11a/g	12.0	6	64	3/4	-	20	54	30
Wi-Fi 4 802.11n	14.4	6	64	5/6	2×2	20	144	115
						40	300	240
Wi-Fi 5 802.11ac	14.4	8	256	5/6	1×1	80	433	375
					2×2	80	866	750
Wi-Fi 6 802.11ax	17.2	10	1024	5/6	2×2	80	1201	1000
						160	2402	1900
Wi-Fi 7 802.11be	17.2	12	4096	5/6	2×2	320	5765	(todo)

¹ Sym=Millions of symbols per second; Bits=bits per symbol; MHz=channel width; Mbps=Max throughput expected

Key 'weak link' example: In mid-2023, Ring introduced a brand new $60 Ring Indoor camera (amazon.com) that only supports (the now very old and slow) Wi-Fi 4. So even with the latest and greatest new Wi-Fi 7 router, this Ring camera can only communicate to that new router at a maximum PHY speed of 72.2 Mbps in only the 2.4 GHz band -- Source (fccid.io).

YOUR client device often limits Mbps speeds, not the router/AP (maximum PHY speed when standing right next to the router)

KEY Wi-Fi concept: Client device capabilities often limit Wi-Fi speeds, not the router/AP.

Analogy: Just because the speed limit on a highway is 65 does not mean that your (speed limited) moped can go that fast. Your actual speed will be the speed limit of the moped. Similarly, in Wi-Fi, your speed is often limited by your client device.

Another example: The Galaxy Tab A8 (a 10.5" tablet), even when connected to the latest and greatest Wi-Fi 7 router, is limited to a PHY speed of 433 Mbps (and max throughput around 300 Mbps) -- because this intentionally 'affordable' class device only supports 1×1 MIMO.

AC5300 4×4 Router to 2×2 Client (at a distance of 32 feet) 5300 ➤ 2166 ➤ 1083 ➤ 866 ➤ 650 ➤ 455

AC5300 4×4 Router to 4×4 Client (at a distance of 32 feet) 5300 ➤ 2166 ➤ 1733 ➤ 1300 ➤ 910

More on bands in the Beware tri-band marketing hype chapter far below.

Wi-Fi specifications for iPhone (apple.com) or iPad (apple.com). Virtually all newer iOS devices are 2×2 MIMO and older iOS devices are 1×1 (no MIMO).

Analogy: Understanding Modulation/Coding: Imagine that once a second (the 'symbol rate' for this channel), you hold up your arms in various positions to convey a message to someone else. If you were only ten feet away from that person, the number of arm positions reliably detected would be very high. But now move 100 feet away. The number of arm positions reliably conveyed would be reduced. Now move 500 feet way. The number of arm positions reliably conveyed might be reduced to just 'did the arm move at all'. The same thing happens in Wi-Fi. If you are close to the AP/router, a large number of bits can be conveyed 'at once' (within each symbol). But as you move away, a smaller and smaller number of bits can be reliably conveyed 'at once'. So 'modulation/coding' is simply how much information can be conveyed at once, and is directly related to distance from the AP/router.

Just Google 802.11ac MAC efficiency (google.com) to understand this issue. In short, there are 'housekeeping' packets that MUST be sent at the SLOWEST possible modulation, and that takes time and slows everything down (along with other issues, see understanding Wi-Fi overhead [§5])

Analogy: You are on a road going 60 mph, but every 100 feet you must slow down to 1 mph for 1.5 feet. Do the math - your average mph is deceptively much lower than you might think. Because what matters is not the (minimal) distance traveled at the slow speed, but the TIME that it takes.

An analogy for all of the above: What if I built a three lane toll road from Washington, DC to New York, NY, and sold passes for chauffeured rides with speeds "up to 74 mph" (AC5300). But after you pay for a ride, you discover that the speed limit is 30 mph (AC2166) on two of the lanes and 14 mph on the third lane. So you take the 30 mph lane, but find out your chauffeur is only driving at 10 mph (MIMO level and QAM) and worse yet, every 100 feet the chauffeur slows down to 1 mph for 10 feet (MAC efficiency). Your average speed is 5 mph. And yet, that is exactly what router manufacturers are doing to you -- AC5300 is really only 455 Mbps for most wireless devices -- just like 74 mph is really 5 mph.

KEY Wi-Fi concept: Client device capabilities often limit Wi-Fi speeds, not the router/AP.

• Wi-Fi 1 [§8], 2 Mbps
• Wi-Fi 2 [§8], 11 Mbps
• Wi-Fi 3 [§8], 54 Mbps
• Wi-Fi 4 [§9], 144 Mbps (20 MHz), or 300 Mbps (40 MHz) -- 64-QAM, 2×2 MIMO
• Wi-Fi 5 [§10], 866 Mbps (80 MHz), or 1733 Mbps (160 MHz) -- 256-QAM, 2×2 MIMO
• Wi-Fi 6 [§11], 1201 Mbps (80 MHz), or 2402 Mbps (160 MHz) -- 1024-QAM, 2×2 MIMO
• Wi-Fi 6E [§12], 2402 Mbps (160 MHz) -- 1024-QAM, 2×2 MIMO

IMPORTANT: After you find PHY speed (below), it is best to run speed tests [§D] to validate actual throughput.

Your device (not the router) is almost certainly limiting Wi-Fi speeds

Expect throughput anywhere from 60% to 80% of PHY speed. So use 70% (±10%) as a fair estimate.

If you don't see 60% to 80% of the PHY speed in a throughput test, then either: (1) the PHY speed you have is not accurate, or (2) there is contention on the channel, like another device is actively using the channel.

UPDATE: The more testing I do, the more it seems like the throughput speed test is more informative about what actual PHY speed was, than the other way around. Namely, throughput speed divided by around 0.7 to 0.8 is a great estimate of what average PHY speed was. Why? Because for me, there are times that reported PHY speed is great, but as soon as I saturate the channel with a speed test, reported PHY takes a dip (during the test), and then after the test, reported PHY goes back to being great. The lesson learned is to scrutinize and collect reported PHY speed during a speed test (not before and not after).

New client devices often outperform older devices: In a real-world test, with Wi-Fi 5 client devices reporting a 2×2 866.6 Mbps PHY link, I measured 461 Mbps (53%) download speeds on one (very old) computer, 540 Mbps (62%) on a second computer, and 673 Mbps (78%) on a third (brand new) computer. All tested just feet away from the same R7800 router. And when testing Wi-Fi 6E devices running in Wi-Fi 5 mode, I get 700 Mbps (81%). So brand new client hardware seems to perform much better than years old client hardware.

PHY speed: When any Wi-Fi device reports a PHY speed to you, take that value with a huge grain of salt. Due to how Wi-Fi works, a device is often constantly adjusting PHY speeds adapting to noise and interference, so the single PHY speed you see is often a best case maximum PHY speed. Namely a device could be using PHY speeds of 78, 104, and 52 Mbps every single second, but will report a PHY speed of 104 Mbps (the maximum) to you.

PHY speed also reveals: (1) channel width, (2) modulation/coding (distance from router), and (3) minimum MIMO level support. Please note that the PHY speed displayed is not a static value, but changes over time, depending upon distance from AP/router, interference, etc.

PHY speed tables: If you don't find your PHY speed in the PHY tables in this paper below [§10], look up the speed in the full PHY speed tables (docs.google.com).

Windows PHY Speed

Example: Lookup 702 Mbps speed (right) in the PHY tables far below [§10] and it is not found. So, go to the full PHY speed tables and you will find various matches, but only one makes logical sense: 80 MHz channel, 2×2 MIMO, 256-QAM.

The PHY speed reported by Windows appears to actually be the maximum of both the Tx PHY and the Rx PHY speeds. Some tests showed the speed reported as the Rx PHY speed. Other tests showed the speed reported as the Tx PHY speed. Also, if Windows is getting the PHY speed from the Wi-Fi driver, this observation could be very Wi-Fi device (and vendor) specific.

Reader TIP #1: if you happen to use Apple's AirPort Wi-Fi base station: "Install Apple's 'AirPort Utility' and then open it. Click on the Wi-Fi base station. Click on 'wireless clients' and then click on your iOS device and then 'connection'. This will give you the iOS device 'PHY' connection speed."

Reader TIP #2: Consider using the "nOversight" app (free version), which shows Tx/Rx rates, plus a lot of other detailed Wi-Fi information.

Android PHY Network Speed

Example: Lookup 585 Mbps (right) in the PHY tables [§10], and you will find it in multiple columns, but given the client, what makes the most sense is: 80 MHz channel width, 2×2 MIMO, and 64-QAM.

It appears that Android reports the "Tx PHY" as the 'link speed'. This is preliminary and needs more research.

• TP-Link TIP: In the TP-Link router web interface, under "Network Map", click on 'Clients' to see a list of all clients, along with "Tx/Rx Rate(Mbps)" PHY speeds (example seen right). Very helpful information to see all devices in a single list, along with PHY information! Best when client devices are actively using the Internet.
• Netgear TIP: In the Netgear 'Nighthawk' router app, click on 'Device Manager', then click on a client device, and a "Link Rate" will be displayed. But Netgear displays a 'link rate' that is slightly too small. To correct (to bps), multiply by 1024/1000 thanks to reader Matthew S. for pointing out that correction.
• Comcast TIP: If you use a Comcast provided cable modem / gateway device, connecting to the http administration interface, signing in, and clicking on the 'View Connected Devices' button will take you to a page that shows the "RSSI Level" (in dBm) for all Wi-Fi connected devices. Very helpful for quickly spotting devices 'in trouble'.

Supporting 4×4 MIMO takes more power, and for battery powered devices, runtime is FAR more important.

You will see the spec sheets for many modern phones that MIMO is 4×4, but look closely and notice that this is only for cellular, not Wi-Fi.

However, of note is that many (non-Apple) Wi-Fi 6/6E devices support 160-MHz channels (HE160), which instantly doubles throughput vs Wi-Fi 5 using 80-MHz channels (VHT80). So speed is increasing dramatically via wider channels, not increased MIMO levels.

A final wrench in the PHY puzzle: And PHY speed is not 'constant'. Unless you are right next to the router (with a fantastic signal strength and PHY speed is highest possible speed), PHY speed is actually constantly changing up and down between MCS levels, adapting to changing signal strength conditions. It is not uncommon with a single second to see 3 to 4 different MCS levels (PHY speeds) used. Are you highly technical? Then use the Router deep dive [§L] appendix below to determine exactly what MCS indexes are being used for both Tx PHY and Rx PHY.

KEY Wi-Fi concept: Expect TPR (throughput to PHY ratio) to be around 70% (±10%) -- or anywhere from 60% to 80%.

What I am beginning to realize is that the PHY speed reported by Wi-Fi devices is often a 'best case' maximum value (and may not accurately reflect the actual PHY speed used). The MCS Spy tool (duckware.com) has been invaluable in detecting and visualizing this during a throughput speed test. PHY speed also can fluctuate a lot up and down, and is not a 'fixed' single value. Also, the newer the device the better. There appears to be some issues with older 802.11ac devices (not achieving top rated speeds).

With both a modern client device and a modern router, and no one else using Wi-Fi -- so NO contention -- I regularly measure a TPR of 80%.

PHY speed in Wi-Fi is exactly like the speed limit (sign) on a local road. You can go that fast some of the time but clearly not all the time. Because you must take into account known slow downs: stop signs, turns, traffic lights, traffic, school zones, weather conditions, etc. And in Wi-Fi, there are a lot of slow downs that also add up.

SSID overhead: The overhead per SSID (on one channel) can be anywhere from 3% to incredibly high. See this article (archive.org), using a 802.11b 1 Mbps beacon rate, for details.

A striking analogy: You are on a road going 120 mph for 5240 feet, and then 1 mph for 40 feet -- What is your average mph for the entire mile (5280 feet)? -- MUCH lower than you might initially expect. The answer is 5280/(5240/120+40/1), or 63 mph! It is not the distance that you slowed down that is important, but rather the time you spend slowed down that really matters (as compared to the time you spend going fast).

So when you are running an ISP download throughput speed test, your device is mostly receiving, but it is also transmitting (acknowledging data sent)! Using the MCS Spy tool, a PC downloaded at 120 Mbps, but was uploading at 1.8 Mbps at the same time. See Router deep dive [§L] appendix below. This is simply due to how TCP/IP works. And almost always, the client transmits back to the AP at a slower MCS than the MCS the router uses to transmit to the client. So because Wi-Fi is half duplex, there may be around 1% to 3% (relative) 'overhead' simply due to how TCP/IP works (acknowledgements).

Analogy: A Wi-Fi channel is just like a Walkie-Talkie, where you can either talk, or listen, but not both at the same time. OR, just like a narrow bridge, where cars (Wi-Fi traffic) can either go one way or the other, but not both ways at the same time.

Consider the impact on a Wi-Fi channel of a video conference call that is both transmitting and receiving 5 Mbps 1080p HQ video streams. 10 Mbps of channel capacity is used.

And if you have a lot to transmit, that 'wait for a random amount of time' over and over adds up. But that random wait is necessary to ensure 'fairness' to other Wi-Fi devices.

CSMA/CA works very well when there are not many devices all wanting to transmit at the same time (which IS typical in Wi-Fi, which is why Wi-Fi mostly works so well). But overhead can increase dramatically if there are too many devices all wanting to transmit at the same time (due to collisions; see below).

From a test AP, there were 1,519,932 packets transmitted and 48,878 packets retransmitted. So, around 3% of the data packets had to be retransmitted.

Wi-Fi hidden node problem

A mitigating factor is that even if your network has the hidden node problem, the hidden nodes will not impact each other, unless they attempt to use Wi-Fi and transmit at the exact same time. If both hidden nodes are sporadically using Wi-Fi, the problem will not happen that often.

How is Wi-Fi spectrum shared? By bandwidth? By time? By something else? In general, by TIME -- if 'N' users all want to use Wi-Fi at the same time, on average, they will all get to use the channel '1/N' of the time. For example, if two users want to use the same channel, and first user at a PHY of 6 Mbps, and the second user at a PHY of 866 Mbps, the first user will get to use the channel 50% of the time (so 6/2, or around 3 Mbps), and the second user will get to use the channel the other 50% of the time (so 866/2, or around 433 Mbps).

This 'a channel is shared' concept is easy to gloss over and not fully understand. But if you see (in a Wi-Fi analyzer app) that your wireless router and other wireless routers (neighbors) on the same channel (or overlapping channels), you are sharing the SAME Wi-Fi spectrum.

A striking example: A laptop in the same room as an AP (on the second floor of a house) with an unobstructed view of the AP gets real-world Tx average throughput of 92 Mbps -- measured using TxRate (duckware.com). But when the laptop is moved downstairs (so now the Wi-Fi signal has to go through walls/floors), Tx throughput increases to a rock solid 116 Mbps. But how is that possible? -- throughput should have decreased! The surprising answer is that downstairs, neighboring Wi-Fi signals were greatly attenuated, so the laptop transmitted more often. And yes, that means the laptop WAS actually transmitting at the same time as a far away station but all that did is raise the noise floor for those transmissions, which were still successfully received.

A prime example: A Windows laptop with an 'older' 802.11ac 2×2 MIMO four feet from the router reports (an expected) 'speed' of 866.6 Mbps (MCS9). A throughput tests shows download speeds of 475 Mbps. That is a MAC efficiency around 55%. But the MCS Spy tool (see Router deep dive [§L] appendix below) clearly shows that the router is transmitting to the PC using only MCS7 (650 Mbps), which is actually a much better MAC efficiency of around 75%. There is still the problem of why MCS9 is being reported and MCS7 used, but MAC efficiency is much better than it initially appears. Take the PHY speed reported by your client device with a 'grain of salt'.

• Wi-Fi Overhead, Part 1: Sources of Overhead (cwnp.com)
• Wi-Fi Overhead, Part 2: Solutions to Overhead (cwnp.com)
• RTS/CTS enhanced with bandwidth signaling (cisco.com)

KEY Wi-Fi concept: There is a lot of marketing hype in the claims made by router companies.

iPhone XS Max

1. Band One: 750 is the maximum PHY speed for MIMO 3×3 in the 2.4 GHz band, but for an unrealistic 1024-QAM (see PHY table far below). A much more realistic PHY speed for a 2×2 MIMO wireless device is 300 Mbps.
2. Band Two: 1625 is the maximum PHY speed for MIMO 3×3 in the 5 GHz band, but for an unrealistic 1024-QAM (see PHY table far below). A much more realistic PHY speed for a 2×2 MIMO wireless device is 650 Mbps (about 32 feet from the router).
3. Band Three: same as band two.

So upgrading to a faster router will increase your iPhone XS Max speeds, right? No! What about an AC5400 4×4 tri-band router? Same speed. What about an ultra-fast Wi-Fi 6 AX6000 8×8 router, marketed as being 4x faster than Wi-Fi 5? Same speed. Understand router manufacturers' marketing hype.

4×4 MIMO illustration

Analogy: Think of MIMO as adding 'decks' to a multi-lane highway. More lanes (capacity) are added without using more land (spectrum). 2×2 MIMO is a highway with one more highway deck above it. And 4×4 MIMO is a highway with three more highway decks above it.

MIMO adds more capacity without using more spectrum! Regardless of the MCS level used (distance between router and router), 2×2 MIMO can transmit twice as much data as 1×1 MIMO can, and 4×4 MIMO can transmit four times as much data as 1×1 MIMO -- in the same amount of time. This is why MIMO is such a big deal -- a direct capacity multiplier.

The huge caveat, of course, is that BOTH the transmitter and receiver must support MIMO. And if each supports different levels of MIMO, the minimum MIMO level common to both devices will be used. For example, a 2×2 MIMO tablet connecting to an 8×8 MIMO router will only use 2×2 MIMO. But as a very significant bonus, the 'extra' antennas (if there is a mismatch in MIMO levels between the client and router) do not go unused, but are used for 'diversity' and 'beamforming', which extends range, and improves speed at range.

NOTE: The 'number of visible antennas' does NOT (necessarily) indicate MIMO level. It may, but it may not. Sometimes antennas are shared between Wi-Fi bands. Sometimes antennas are dedicated to just a single Wi-Fi band so 2× or 3× as many antennas as MIMO level. Some routers use a mix of both internal and external antennas. Some Wi-Fi 6E routers are moving to all internal antennas.

1×1 MIMO	2×2 MIMO	4×4 MIMO

• 1×1 MIMO yields a PHY of 433 Mbps
• 2×2 MIMO yields a PHY of 866 Mbps (most wireless clients are 2×2)
• 3×3 MIMO yields a PHY of 1300 Mbps
• 4×4 MIMO yields a PHY of 1733 Mbps (most higher end routers are 4×4)
• 8×8 MIMO yields a PHY of 3466 Mbps

FCC documents discuss that the 'maximum' gain when doubling antennas is 10×log(N_ANT/N_SS) dBi, which for a 2×2 client to a 4×4 access point, would result in a diversity gain of 'around' 3 dBi. OR a 4×4 access point to a 1×1 client means a diversity gain 'around' 6 dBi.

This explain why you really do want a 4×4 MIMO router, even though there may only be 1×1 and 2×2 client devices connecting to it!

Comcast XB6 gateway - 8×8 MIMO

A very nice explanation of beamforming! (youtube.com)

KEY Wi-Fi concept: It is easy to overlook and miss, but beamforming and diversity are the key reasons why you want a 4×4 MIMO router even though most clients are still only 2×2 MIMO. The extra antennas are actually used and offer significant value (a stronger signal, which translate to better connect speeds for far-away users)!

AX 'Stream' Deception: Router vendors' are now being incredibly deceptive when it comes to advertising in their new "AX" class of routers. Details [§Q]. Netgear is using "spatial streams" to describe their new AX routers (netgear.com), but this is NOT the same thing as "spatial streams" in MIMO in the 802.11ax standard -- which is what most people will (wrongly) conclude -- and that is outright deceptive, and Netgear knows it (because when I mentioned this in a Netgear forum post, a Netgear moderator deleted my post). Netgear claims their new RAX80 4×4 four-antenna (four spatial streams) router is "8 streams" (netgear.com). So, do your research, and buyer beware. Netgear's "spatial stream" logic is provably wrong. The maximum number of 'streams' in a router can not be larger than the number of antennas in the router. because "In the T×R configuration the maximum number of spatial streams is limited by the lesser of either T or R". Source (cisco.com). A pattern emerges: Router vendors are incredibly 'creative' in their marketing of new routers. They are constantly figuring out creative ways to make new hardware sound 'so much better' than older similar hardware.

• EXCELLENT: 802.11ax Frequently Asked Questions (aerohive.com via archive.org)
• MIMO: Why multiple antennas matter (cisco.com)
• FAQ: MIMO, MRC, Beamforming, STBC, and Spatial Multiplexing (huawei.com)
• MIMO Communications (youtube.com)

Gen	Spec	Year	PHY Speeds	Unofficial name	Band
First	802.11	1997	2 Mbps	Wi-Fi 1	2.4 GHz
Second	802.11b	1999	11 Mbps	Wi-Fi 2	2.4 GHz
Third	802.11a	2001	54 Mbps	Wi-Fi 3	5 GHz
Third	802.11g	2002	54 Mbps	Wi-Fi 3E	2.4 GHz

KEY Wi-Fi concept: Wi-Fi works BEST (fastest) when you are close to an access point.

802.11a/g PHY Speeds 20 MHz channel 800ns guard interval Modulation + Coding Mbps 0 BPSK 1/2 6.0 1 3/4 9.0 2 QPSK 1/2 12.0 3 3/4 18.0 4 16‑QAM 1/2 24.0 5 3/4 36.0 6 64‑QAM 2/3 48.0 7 3/4 54.0 More PHY tables

The router industry learned a very hard lesson about the 'consumer market' -- that any new router/AP must also be fully backward compatible (must support most, if not all, of the old client devices out there)!

New routers today support ALL prior generations of Wi-Fi back to 802.11b.

Note that 64-QAM 5/6 is not a part of Wi-Fi 3. That arrives in the next Wi-Fi generation, Wi-Fi 4.

Linksys WRT54G (a big hit back in the day)

A note about channels: In the U.S. there are 11 overlapping Wi-Fi channels in 2.4 GHz. The only way to get non-overlapping channels is for all routers/AP to cooperate and set their channels to either 1, 6, or 11. But when I use a Wi-Fi analyzer, I see routers operating on other channels all of the time. Be a nice neighbor and only use channels 1, 6, or 11. See the drawing in the next chapter [§9] for more details.

• Wi-Fi (802.11) PHY Data Rates (blogspot.com) -- Understand how PHY rates are computed
• Different Wi-Fi Protocols and Data Rates (intel.com)

Gen	Spec	Year	PHY Speeds	New Name
Fourth	802.11n	2006	72 to 217 Mbps	Wi-Fi 4

802.11n is called "HT" for High Throughput

Let that sink in. Only 70 MHz of spectrum in 2.4 GHz must be shared between you, your family, and a bunch of neighbors.

Technically, channels 12 and 13 could be used in the US, but under significant restrictions that in reality, cause all routers/clients to elect to not touch those channels. Details (wikipedia.org)

2.4 GHz Wi-Fi has only THREE non-overlapping channels

More Info: Video about channels 1/6/11 from MetaGeek (youtube.com)

An analogy: A router using channel 2, 3, 4, 5, or 7, 8, 9, 10 (instead of channel 1, 6, or 11) is exactly like a car on a three lane Intestate driving directly over the dashed lane divider lines and refusing to move over fully into a lane. That 'car' gets to its destination, but in the process, then impacts TWO lanes on the Interstate, instead of just one lane.

Screenshot from 'RF-Explorer Handheld Spectrum Analyzer'

But what about the 'four-channel plan' overseas using channel 1, 5, 9, 13? That can only work well when adjacent channels are not actively being used!. There is now NO 5 MHz space between channels, so the bleed over [§S] from the sideband signal in adjacent channels will be even more pronounced -- and be even more impactful. When Wi-Fi is heavily used, it is best to stick with only using channels 1, 6, 11.

In a very 'clean' Wi-Fi environment, I have seen throughput [§D] around 54.2 Mbps for a PHY speed of 72.2 Mbps, which comes out to 75% efficiency -- pretty good. Another time, when I was just feet from the router, I measured a peak throughput of around 118 Mbps for a PHY speed of 144.4 Mbps (82% efficiency) -- very good.

802.11n PHY Speeds (Mbps) 20 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 0 BPSK 1/2 7.2 14.4 21.6 28.8 1 QPSK 1/2 14.4 28.8 43.3 57.7 2 3/4 21.6 43.3 65.0 86.6 3 16‑QAM 1/2 28.8 57.7 86.6 115.5 4 3/4 43.3 86.6 130.0 173.3 5 64‑QAM 2/3 57.7 115.6 173.3 231.1 6 3/4 65.0 130.0 195.0 260.0 7 5/6 72.2 144.4 216.6 288.8 - 256‑QAM 3/4 86.6 173.3 260.0 346.6 - 5/6 96.2 192.5 288.8 385.1 - 1024‑QAM 3/4 108.3 216.6 325.0 433.3 - 5/6 120.3 240.7 361.1 481.4 256-QAM and 1024-QAM are non-standard 802.11n PHY Speeds (Mbps) 40 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 0 BPSK 1/2 15 30 45 60 1 QPSK 1/2 30 60 90 120 2 3/4 45 90 135 180 3 16‑QAM 1/2 60 120 180 240 4 3/4 90 180 270 360 5 64‑QAM 2/3 120 240 360 480 6 3/4 135 270 405 540 7 5/6 150 300 450 600 - 256‑QAM 3/4 180 360 540 720 - 5/6 200 400 600 800 - 1024‑QAM 3/4 225 450 675 900 - 5/6 250 500 750 1000 256-QAM and 1024-QAM are non-standard More PHY speed tables

Analogy: Think of channel width as how many 'lanes' you can use at once on a multi-lane highway. 20 MHz is a car using a single lane. 40 MHz is a 'wide' load trailer using two full highway lanes.

Great article on the subject: "Bye Bye 40 MHz Mode in 2.4 GHz" (smallnetbuilder.com)

I am curious if this issue had anything to do with why Netgear stopped getting their routers 'Wi-Fi Certified'?

Or, if there is a single 20 MHz only client that connects to the AP, the AP will (should) drop from 40 MHz operation to 20 MHz operation, disabling channel bonding. This situation is actually VERY likely to happen (for example, my daughter's very inexpensive laptop that is only two years old, but only supports 20 MHz channels).

Virtually all (inexpensive) IoT devices only support 20 MHz channels.

Also, in the real world, things are MUCH more complicated, because many routers don't always follow 'good neighbor' standards try to force and use 40 MHz channels when they should only be using 20 MHz channels.

Of note is that 40 MHz channels in the 5 GHz band for 802.11n does work -- very well.

The reason why 256-QAM and 1024-QAM are included in the PHY tables here is for reference/convenience -- because these PHY tables ARE ALSO the PHY speed tables for 802.11ac for 20 MHz and 40 MHz channel widths. The PHY speeds for an 80 MHz channel is far below in the next chapter.

Major interference (in red) caused by a Microwave Oven (for a couple seconds)

Microwave ovens are licensed in the entire ISM (Industrial, Scientific and Medical) band from 2.4 GHz to 2.5 GHz, which covers all 2.4 GHz Wi-Fi channels. Example (fccid.io).

How bad the interference is totally depends upon the specific microwave. Some microwaves are very bad, while others seem to have very little impact. At one house, using the microwave oven causes Wi-Fi clients to disconnect from the AP, while in another house, using the microwave oven only causes a slight slowdown in bandwidth to Wi-Fi clients.

Years ago I was testing a Wi-Fi security camera (base station and cam connected via 2.4 GHz), and just happened to use the microwave oven, and noticed the cam was unable to record any video. I learned my lesson and immediately returned the camera.

Is your house near a busy road? If so, you are likely getting some interference from all the cars driving by that are operating a 'hotspot' (likely always enabled, although maybe not with Internet activated). And the worst part is, you can NOT plan for that channel usage, because the cars are mobile!

The real impact of overcrowding: In a beach resort community, with homes very close to each other, a Wi-Fi analyzer app shows well over fifteen 2.4 GHz networks within range. At night, Wi-Fi performance (actual throughput) on the 2.4 GHz band was horrible (even with great PHY speed) due to contention (sharing bandwidth) with many neighbors. However, performance on the 5 GHz band was excellent.

Example: In mid-2023, Ring introduced a new $60 Ring Indoor camera (amazon.com) that supports ONLY 2.4 GHz (and no MIMO). And since it is plugged in all the time to an outlet, that seems very short-sighted (especially when I can find smart plugs for $8 on Amazon that support 5 GHz Wi-Fi). If the 2.4 GHz Wi-Fi band still works OK for you, then no problem. But if 2.4 GHz is too congested at your physical location, then this camera will not work well for you. Buyer beware.

• Understanding High Speed 802.11n Wireless Networks in Depth (cisco.com)

Gen	Spec	Year	PHY Speeds	New Name
Fifth	802.11ac	2013	433 to 1733 Mbps	Wi-Fi 5

802.11ac is called "VHT" for Very High Throughput

BEWARE: Many entry-level low-end routers only support 180 MHz of the 5 GHz spectrum (not all 560 MHz).

NOTE: One 80 MHz channel in 5 GHz has more spectrum than ALL 2.4 GHz channels, combined!

Channel Use Restriction: 16 (seen in red, right) of the 25 channels (or 64%) come with a critical FCC restriction (DFS - dynamic frequency selection) to avoid interference with existing devices operating in that band (weather-radar and military applications). Very few 'consumer-grade' access points support ALL of these 'restricted' channels, whereas many 'enterprise-grade' access points DO support these channels. More on this later in this chapter. 802.11h defines (1) dynamic frequency selection (DFS) and (2) transmit power control (TPC).

Channel 144: This channel was added as part of FCC changes in 2014. So this channel will be problematic for older devices that don't recognize this channel. Worst of all is that some brand new devices also mess up and don't support channel 144, so it is best to avoid selecting 144 as a 'primary' channel in most routers -- because if you do, a small subset of clients will not be able to connect to your router. Devices that don't recognize 20 MHz channel 144, also by definition don't recognize 40 MHz channel 142 and 80 MHz channel 138 (so a client device may have limited channel width when connecting to an AP using primary channels 132, 136, or 140).

For example, Ring video doorbell cams that operate in 5 GHz don't understand that channel 144 exists. The cam will NOT connect to an AP on channel 144, and will only connect to an AP on channel 140 using a 20 MHz channel (not 40 MHz).

120/124/128: Terminal Doppler Weather Radar (TDWR): If you are 'near' a major metropolitan airport, you might not be able to use 20 MHz channels 120, 124, or 128 (and hence 80 MHz channel 122) due to use of Terminal Doppler Weather Radar operating within 5600-5650 MHz at a peak power of 250,000 watts. TDWR locations and frequencies (wispa.org). See also Terminal Doppler Weather Radar (wikipedia.org) and a Weather Radio Channels (cisco.com) on the TDWR issue. Channels affected are in dark red (above right).

New channels: In mid December 2019, the FCC voted (fcc.gov) to move forward on allocating an additional 45 MHz to the end of U-NII-3 in 5.9 GHz to Wi-Fi (seen in yellow in table right). This results in three NEW 20 MHz channels (169, 173, 177). See also FCC 19-129 (govinfo.gov). This also creates two additional 40 MHz channels (167, 175), one new 80 MHz channel (171), and one new non-DFS 160 MHz channel (163). But, the big problem is that these new channels are for INDOOR USE ONLY. See FCC guidelines (fcc.gov). Also, given that Wi-Fi 6E now exists (with 1200 MHz of new spectrum), the value of these new channels in 5 GHz is GREATLY diminished -- because existing Wi-Fi 5 devices don't know about these new channels (and will fail to connect to a router using them) and new devices capable of recognizing the new channels will just use the Wi-Fi 6E channels instead.

Center Frequency TIP: The 'center frequency' (in MHz) of any 5 GHz channel number is simply that channel number multiplied by five (and added to 5000). For example, the center frequency of channel 60 is 5000 + 60×5 = 5300 MHz. Or, reverse to compute channel number from center frequency.

Channel 165: ONLY select channel 165 when the router is configured for 20 MHz channel widths. Because if you select channel 165 when the router is configured to use 160/80/40 MHz channel widths, there are actually NO available 160/80/40 MHz channels -- NONE! Wi-Fi clients will ONLY be able to connect to 20 MHz channel 165! This behavior was first noticed on a Netgear R7800 router.

Other routers are smart enough to not show channel 165 (unless the router is configured to only use 20 MHz channels).

This 'automatic' selection of the appropriate 160/80/40 channel from a single 20 MHz channel that you select totally sidesteps the problem of one (misaligned) wide channel straddling two other wide channels.

With 5 GHz, neighbors can (often times) be on the same channel and typically not interfere with each other (nearly as much as 2.4 GHz), because with reduced range, neighbors can't see as many neighbors Wi-Fi anymore. Of course, all of this depends upon how 'close' your neighbors are.

• 802.11 Channel Plans New Rules v02 (fcc.gov) - This is just the chart above
• Code of Federal Regulations (ecfr.gov) - The actual Federal Code governing the Wi-Fi spectrum
• Straddle channels (fcc.gov) - treatment of channels that straddle U-NII bands

Many residential routers have a transmit power around 995 mW. Many (battery powered) Wi-Fi clients have a transmit power anywhere from 90 mW to 250 mW. Client devices often transmit at power levels below the maximum power level permitted. More information [§H]

802.11ac PHY Speeds (Mbps) 80 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 32 65 97 130 260 1 QPSK 1/2 65 130 195 260 520 2 3/4 97 195 292 390 780 3 16‑QAM 1/2 130 260 390 520 1040 4 3/4 195 390 585 780 1560 5 64‑QAM 2/3 260 520 780 1040 2080 6 3/4 292 585 877 1170 2340 7 5/6 325 650 975 1300 2600 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 390 780 1170 1560 3120 9 5/6 433 866 1300 1733 3466 - 1024‑QAM 3/4 487 975 1462 1950 3900 - 5/6 541 1083 1625 2166 4333 1024-QAM is non-standard 802.11ac PHY Speeds (Mbps) 80 MHz channel, 800ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 29 58 87 117 234 1 QPSK 1/2 58 117 175 234 468 2 3/4 87 175 263 351 702 3 16‑QAM 1/2 117 234 351 468 936 4 3/4 175 351 526 702 1404 5 64‑QAM 2/3 234 468 702 936 1872 6 3/4 263 526 789 1053 2106 7 5/6 292 585 877 1170 2340 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 351 702 1053 1404 2808 9 5/6 390 780 1170 1560 3120 - 1024‑QAM 3/4 438 877 1316 1755 3510 - 5/6 487 975 1462 1950 3900 1024-QAM is non-standard More PHY speed tables

Your mileage will vary depending upon construction materials. In one home (single level; sheetrock with aluminum studs), I saw a dramatic increase in speeds at range. But at an older second home with very thick brick walls, range improved just a little.

Buyer beware: Not all 'wave 2' products will support the restrictive 5 GHz DFS channels! Wi-Fi certification for 'wave 2' only 'encourages' (wi-fi.org) devices to support this -- so NOT required.

160 MHz channels: Support for 160 MHz channels in some routers reduces MIMO support. For example, in Netgear's R7800, there is 4×4 MIMO support for 80 MHz channels, but for 160 MHz channels, MIMO is reduced to 2×2.

MU-MIMO issues: There are a lot of issues with MU-MIMO. So it may or may not work for you. MU-MIMO (1) sometimes disables client MIMO (smallnetbuilder.com) (where a 2×2 client switches to 1×1; Broadcom chipset) (2) requires spatial diversity (physical distance) (archive.org) between clients (3) has significant sounding overhead (youtube.com) (4) a client device must be MU-MIMO aware (many are not) (5) only works with high SNR (very strong signals) and (6) works best with completely stationary clients. For more details, read "A MU-MIMO Reality Check" (networkcomputing.com). Aruba Networks says "Experience from 802.11ac MU-MIMO in real-world deployments revealed some limitations". Source (arubanetworks.com). More info (youtube.com).

Another example: An older Dell laptop using Centrino Advanced-N 6230 dual-band (intel.com) Wi-Fi. The laptop 'sees' the 5 GHz SSID being broadcast from a 802.11ac router, but when the laptop connects to the router, it is only doing so using 802.11n, 2×2 MIMO, and 40 MHz channels (max PHY of 300 Mbps; no 256-QAM)

• O'Reilly '802.11ac: A Survival Guide' by Matthew S. Gast (cmu.edu) -- 154 page book
• 802.11ac In-Depth (arubanetworks.com)
• Technical White Paper: "802.11ac: The Fifth Generation of Wi-Fi" (cisco.com)
• 802.11ac (wikipedia.org)
• Clients List (mikealbano.com) - lists common Wi-Fi clients and the channels they support
• United States Frequency Allocations Chart (ntia.doc.gov) - Who is using what parts of the radio spectrum
• Eero 160MHz over 5GHz FAQ regarding Apple devices
• 802.11ac and Wi-Fi Radio Fundamentals (youtube.com)

Note that 160 MHz channel support in battery powered Wi-Fi 6 client devices is MUCH more common than in Wi-Fi 5 devices -- So while 160 MHz channels are NOT a new feature of Wi-Fi 6, as a practical matter, Wi-Fi 6 may be the first version of Wi-Fi that regularly delivers on 160 MHz channels for client devices, and allows 1 Gbps throughput to be regularly achieved.

Gen	Spec	Year	PHY Speeds	New Name
Sixth	802.11ax	2019	600 to 4804 Mbps	Wi-Fi 6

802.11ax PHY Speeds (Mbps) 80 MHz channel, 800ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 36 72 108 144 288 1 QPSK 1/2 72 144 216 288 576 2 3/4 108 216 324 432 864 3 16‑QAM 1/2 144 288 432 576 1152 4 3/4 216 432 648 864 1729 5 64‑QAM 2/3 288 576 864 1152 2305 6 3/4 324 648 972 1297 2594 7 5/6 360 720 1080 1441 2882 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 432 864 1297 1729 3458 9 5/6 480 960 1441 1921 3843 10 1024‑QAM 3/4 540 1080 1621 2161 4323 11 5/6 600 1200 1801 2401 4803 802.11ax PHY Speeds (Mbps) 80 MHz channel, 1600ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 34 68 102 136 272 1 QPSK 1/2 68 136 204 272 544 2 3/4 102 204 306 408 816 3 16‑QAM 1/2 136 272 408 544 1088 4 3/4 204 408 612 816 1633 5 64‑QAM 2/3 272 544 816 1088 2177 6 3/4 306 612 918 1225 2450 7 5/6 340 680 1020 1361 2722 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 408 816 1225 1633 3266 9 5/6 453 907 1361 1814 3629 10 1024‑QAM 3/4 510 1020 1531 2041 4083 11 5/6 567 1134 1701 2268 4537 More PHY speed tables

802.11ax is called "HE" for High Efficiency

Multi-user support is baked into OFDMA: This is a critical concept to fully understand about Wi-Fi 6. In Wi-Fi 5, 'multi-user' was accomplished via MU-MIMO using multiple antennas. HOWEVER, in Wi-Fi 6, there is a SECOND (and now primary) 'multi-user' method 'baked' into the protocols called MU-OFDMA. Don't confuse MU-OFDMA with MU-MIMO! (archive.org) Also, see this interesting MU-OFDMA vs MU-MIMO (archive.org) article.

This multi-user support is a big deal, and will greatly improve Wi-Fi for all -- but it will take many YEARS before most clients are 802.11ax. So don't expect to see Wi-Fi 6 benefits for YEARS.

The goal of every prior version of Wi-Fi was dramatically increasing 'peak' speeds (for one user). And by looking at Wi-Fi generation Mbps speeds, you can see this: 2 -> 11 -> 54 -> 217 -> 1733 -> 2401, except for the last jump, which is Wi-Fi 6. Instead, by changing to MU-OFDMA in Wi-Fi 6, there will be dramatic (overall) capacity gains to a dense set of users (as a whole), but only when (all) clients fully support Wi-Fi 6.

Support for 160 MHz channels in some routers reduces MIMO support. For example, in Netgear's RAX120, there is 8×8 MIMO support for 80 MHz channels, but only 4×4 MIMO support for 80+80 channels.

6 GHz spectrum: The FCC opened up the 6 GHz and for Wi-Fi (but this requires new hardware). See Wi-Fi 6E [§12] in the next chapter. This will make 160 MHz channels commonplace.

Very deceptive router manufacturer speed comparison

Analogy: It should be painfully obvious by now that router manufacturers are selling you on hype. They are selling you on a 'dragstrip' (the router), where you can 'legally' go '1000 mph' -- and that sounds fantastic, so you buy the dragstrip (router). But then you step back and realize that (1) all the vehicles (Wi-Fi devices) you own don't go over 120 mph, (2) you can buy faster cars but they are not legal for you (desktops have faster Wi-Fi than smartphones), and (3) 1000 mph was obtained by adding the speeds of multiple cars together (aggregating multiple Wi-Fi bands).

"The bottom line is until Wi-Fi 6 / 802.11ax clients reach critical mass, the benefits of 11ax are minimal and will have low impact". Source (cisco.com). "For [most enterprise customers], we recommend installing 802.11ac wave 2 access points today, because of the sheer value of 802.11ac wave 2". Source (cisco.com). Consumer Reports concludes (consumerreports.org) that "there is very little point in buying a new Wi-Fi 6 router, especially if your smartphone, TV, laptop, etc. only support Wi-Fi 5".

Also, if your client device is in the same room as a Wi-Fi 6 wireless router (so not 'at distance'), you may see a modest speed boost using Wi-Fi 6 over Wi-Fi 5.

Warning: There are currently NO Apple Mac/iPhone/iPad client devices that support HE160 in Wi-Fi 6 in the 5 GHz band. Apple currently only supports 160 MHz channels with Wi-Fi 6E in the 6 GHz band.

WARNING: Pay close attention to PHY speeds, because the ability to successfully use QAM-1024 (or not) will impact throughput results, which is mostly 'out of your control' (just the RF environment at your location).

• 802.11ax High Level Overview (youtube.com) -- Video by Ruckus
• White paper on 802.11ax (arubanetworks.com)
• Technical White Paper: "802.11ax: The Sixth Generation of Wi-Fi" (cisco.com)
• White Paper: IEEE 802.11ax, The Sixth Generation of Wi-Fi (broadcom.com)
• Dual-Band 11AX (quantenna.com)
• 802.11ax (wikipedia.org)
• 802.11ax Resource Units (wikipedia.org)
• What is 802.11ax Wi-Fi (ruckusnetworks.com)
• High Efficiency Wi-Fi- 802.11ax - WLPC US Phoenix 2017 (youtube.com)

Wi-Fi 6 in the 5 GHz band DOES have 160 MHz channels, but usage is not guaranteed since 160 MHz channels overlap with DFS channels. Meaning that you can attempt to use the channels, but that the router may detect a DFS conflict and automatically revert back to a non-DFS 80 MHz channel.

There is only 560 MHz of spectrum currently available to Wi-Fi in 5 GHz (and only 70 MHz in 2.4 GHz). So adding an additional 1200 MHz in 6 GHz is a very welcome and significant jump in spectrum.

Apple has finally started to offer HE160 in Wi-Fi 6E, but only for the highest top-of-the-line Mac/iPhone/iPad models, and only in 6 GHz (not in 5 GHz).

Many entry-level Wi-Fi 5 routers (with no DFS support) only support 180 MHz of spectrum. But I expect entry-level Wi-Fi 6E routers (with no AFC support) to support all 1200 MHz of spectrum.

Also of note is that Wi-Fi currently has no 160 MHz channel that is not subject to DFS restrictions, meaning that currently, actually being able to use a 160 MHz channel today in 5 GHz is hit or miss. This new spectrum should (hopefully) make it much easier to find and actually use multiple 160 MHz channels.

Wi-Fi 6E access points in low-power mode are permitted to operate at 24 dBm EIRP (6 dB BELOW 5 GHz DFS power levels), and Wi-Fi 6E clients at 18 dBm EIRP (6 dB BELOW that of the AP). Many Wi-Fi 5 clients today already operate 'around' this power level, so Wi-Fi 6E range will be affected by the slightly higher operating frequencies, and the 6 dB power difference (below DFS).

A change in Wi-Fi 6E, for the 6 GHz spectrum, is that clients will now operate at a constant 5 dBM/MHz PSD (Power Spectral Density).

Wi-Fi 6E access points in normal-power mode are permitted to operate at 36 dBm EIRP (the same power levels of 5 GHz U-NII-1 power levels), and Wi-Fi 6E clients at 30 dBm EIRP (6 dB BELOW that of the AP). Most Wi-Fi 5 devices already operate below these levels, so Wi-Fi 6E range will be affected only by the slightly higher operating frequencies.

Privacy mitigating factors: An access point can operate in 'low power mode' and then NOT be subject to AFC (but then signal range WILL suffer) OR, the access point can reduce the GPS quality and then report a larger general 'area' to the AFC instead of an exact location (but then frequencies and power levels that can be used might be reduced).

In some of my speed testing 'at distance', 5 GHz channels are providing much better real Mbps throughput than 6 GHz channels. This needs more research.

Incumbent Services: The FCC did not just have 1200 MHz of spectrum laying around unused. Instead, this spectrum is heavily used by 'incumbent services', such as:

1. Fixed Microwave Services (FS): You have probably seen these towers around with a 'dish' pointed in a fixed (horizontal) direction. Just Google microwave tower (google.com).
2. Fixed Satellite Services (FSS): Ground to satellite communication (and vice-versa).
3. Radio Astronomy: The study of celestial objects at radio frequencies.
4. Other miscellaneous services: Mobile services, etc.

Interesting: Video showing FS usage in the US (youtube.com)

The thinking is that with Wi-Fi 6E and 160 MHz channels, a 2 Gbps PHY connection with reliable 1 Gbps actual throughput becomes commonplace (instead of hit or miss) when are you in the same room as the access point -- with only a 2×2 MIMO client device.

• Low-power access points can use the entire 1200 MHz spectrum, but use is restricted to indoor use only, and range will be limited. These low-power devices cannot be weather resistant, must have permanently attached integrated antennas, cannot be battery powered, and must be labeled "for indoor use only".
• Normal-power access points can be used outdoors, but must use AFC, and are restricted to using U-NII-5 or U-NII-7.
• Client devices are prohibited from being used as a mobile hotspot.
• Access points are prohibited in moving vehicles such as cars, trains, ships, or small aircraft (but with an exception for large passenger aircraft operating over 10,000 feet, but may only use U-NII-5).
• Access points are prohibited on ships and oil platforms.
• Use is prohibited on unmanned aircraft systems.
• Devices using AFC must report geo-location, geo-location accuracy, antenna height above ground, device FCC ID, and device serial number to a centralized AFC database, which then returns frequencies and power levels that may be used. The device must contact the AFC database at least once per day (failure means stop working; with one day grace period)
• Assumes that there will be 17 dB in signal loss when the signal from an indoor access point travels outside through a building's walls.
• Sets a maximum channel width of 320 MHz.
• Client devices are prohibited from transmitting anything until the device hears something from an access point (so no probe requests).
• Client devices must operate at 6 dB below the power level of the access point power level.
• An underlying AFC presumption is that access points are at a fixed location (not mobile nor moving around).

• FCC Opens 6 GHz Band to Wi-Fi and Other Unlicensed Uses (fcc.gov)
• FCC Technical Report and Order 20-51 (fcc.gov)
• Power Spectral Density and Wi-Fi 6E (juniper.net)

It will take time for Wi-Fi 7 implementations to mature, become stable, and actually implement all Wi-Fi 7 features. I see Wi-Fi 7 routers being sold today that:

• promise to implement MLO in a future firmware version
• state "This router may not support all the mandatory features as ratified in the IEEE 802.11be specification"

So frankly, buyer beware!

Gen	Spec	Year	PHY Speeds	New Name
Seventh	802.11be	2023	(todo)	Wi-Fi 7

• 320 MHz channels contiguous (320 MHz) or non-contiguous (160+160 MHz)
• 240 MHz channels contiguous (240 MHz) or non-contiguous (160+80 MHz)
• allows 16×16 MIMO / spatial streams (vs prior 8×8 limit) -- but only expect 2×2 in virtually all client devices, and 4×4 in most mid to higher end routers
• 4096-QAM modulation (vs prior 1024-QAM) -- but only obtainable if you are VERY close to the router, and are line-of-sight (no obstacles)
• Multi-Link Operation, or MLO, uses multiple bands/channels at the SAME time -- for example using 2.4 GHz, 5 GHz, and 6 GHz all concurrently.
• Preamble Puncturing - if part of a 'wide' channel is being used by an old legacy client device, the rest of the channel can still be used by a modern Wi-Fi device
• plus other potential new features (as the Wi-Fi 7 specification has not yet been 'ratified' -- expected in early 2024)

802.11be is called "EHT" for Extremely High Throughput

TP-Link BE550

Expect speeds to drop very quickly with distance.

Is 4096 QAM even possible? "The answer is a mixed bag. Possible? Yes, as Wi-Fi 7 Extremely High Throughput does add the features needed, it is possible to achieve this in the wild. Is it probable? Probably not in many scenarios. While very cool and very fast, it's also fragile and we expect to only see this level of modulation in a small number of instances." Source (ruckusnetworks.com)

So we are being 'sold' something that -- for all practical purposes -- we can rarely use! For now, 1024-QAM is a reasonable maximum QAM.

Q: Can any reader point me to an online review and Wi-Fi 7 speed test that shows 4096-QAM actually being successfully used?

I see one mesh network system dealing with this by adding a non-MLO 240 MHz backhaul channel in 5 GHz (quad-band). Don't expect mesh systems to deliver MLO throughput speeds all the way from client device to the main router from a satellite mesh node. The speed advantages that Access Points have over mesh systems will become much more obvious with Wi-Fi 7.

UPDATE: Beware that some very inexpensive routers might only support a SINGLE 5 GHz channel. Just do your research before a purchase!

(1) Many Netgear Wi-Fi 5 routers do not support CH 144, and as such, can't support 80 MHz channel 138. This flaw was fixed in Netgear Wi-Fi 6 routers.

(2) The FCC added 20 MHz channels 169, 173, and 177 in 2019 (for indoor use only), which also creates a new 80 MHz channel 171. But don't expect support in very many devices (yet) for the new channels.

Also, this is especially important if you can see several other 5 GHz AP's, which happens when you (1) have close neighbors like in an apartment building, or (2) want to install multiple AP/routers. So, only consider AP/routers that support ALL the DFS channels.

Netgear ALERT: Most Netgear routers don't support 80 MHz channel 138. But this is slowly changing. The R7800 is a rare exception, supporting channel 138, but only via firmware 1.0.2.68. Also, it appears that Netgear is finally 'aware' of the issue as some of the newer 'AX' hardware also supports channel 138.

Most of the Netgear business access points (Netgear ProSafe Access Points) do NOT support the restricted 5 GHz channels. But I did find ONE that did. Just do your research.

For example, I was in a Drury Hotel and from my room, I could see the Drury SSID on channels 48, 64, 100, 104, 108, 140. So the hotel was clearly using DFS certified 5 GHz access points -- successfully.

FCC Operating Frequencies show DFS support

1. Google 'fccid.io' and 'FCC' and the router vendor name and model.
2. Look for a google search result to the fccid.io web site with 'FCC' in the link and click on the link. If not on the 'home page' for the router, there will be link near the top of the page home page for that device.
3. As best you can, confirm that you found the correct router by looking at the 'external photos' document. Once confirmed, go back to the previous (home) page.
4. In the resulting home web page, look for the "Operating Frequencies" section (example seen right).
5. Look for frequencies that cover the DFS channel range (highlighted in yellow right). [Frequency ranges are usually based upon '20 MHz center' values]. If so, that router/AP HAS DFS channel support. Otherwise, there is NO DFS channel support. For the RAX80, notice that it appears that DFS channels are supported (except for channel 144), which then also excludes channels 142 and channel 138 -- because the GHz range stops at 5.7 GHz instead of 5.72 GHz).
6. Look for the 'DFS Test Report' and see if the device is a master or a slave, or both (see immediately below). You are looking for 'master' (router) support.

Netgear was plain lazy: Netgear got the R6700v3 certified as a DFS Master (fccid.io), or Wi-Fi router mode, but failed to get the router certified as a DFS Slave (Wi-Fi client mode). This matters if you use the R6700v3 as a 'wireless bridge' (to connect 'ethernet only' devices to your main Wi-Fi router), because all of a sudden, in that mode, the R6700v3 no longer supports DFS channels -- meaning that if you bought the R6700v3 to connect to your main router (broadcasting/using a DFS channel), the R6700v3 will NOT work!

I have even selected a DFS channel and seen it work for weeks, only for the router to then all of a sudden auto select a non-DFS channel (meaning the router detected a 'conflict'). Was this a real radar signal detected, or a false alarm (most likely)? You just need to be patient finding a DFS channel that works long-term for you.

Often times, when a router automatically switches to a non-DFS channel, that change is temporary -- as simply power cycling the router will cause the router to once again use the (configured) DFS channel.

A Wi-Fi client not supporting DFS channels is very rare -- and is definitely incredible laziness on the part of the device manufacturer. Often times, you will never actually notice, because the problem device will just connect to the router's slower 2.4 GHz band, ignoring the fast 5 GHz DFS band.

Multiple readers have told me that most Roku devices do not support DFS channels! And Roku's own support article confirms this. That is crazy laziness on Roku's part, and is not at all customer friendly.

Netgear R7800 wireless setup

You can use different SSID names, but then you don't get Wi-Fi roaming.

The problem with the 'same name' technique is that some client devices are 'dumb' and incorrectly connect to the 2.4 GHz band instead of the 5 GHz band (and then speeds are much slower than they should be). I had this problem with a laptop that would initially start out connected to the (fast) 5 GHz band, but after about 10 minutes, it would then switch to the (much slower) 2.4 GHz band (for unknown reasons). Yes, the 5 GHz RSSI signal was weaker, but throughput from 5 GHz was MUCH better. I fixed by appending a "-5G" to the 5 GHz band SSID, and connecting to that SSID.

TIP: Under Windows, look at your Wi-Fi device in the 'Device Manager' -- there may be an option called 'Preferred Band' that is set to 'auto'. Change to attempt to force your device to use a particular Wi-Fi band.

The bottom line: Be practical. Just use whatever SSID naming method works best for you and your devices.

Router "Smart Connect" TIP: If you want to 'split' the SSID names for your Wi-Fi bands, first turn the 'Smart Connect' feature OFF (as that feature 'on' forces the SSID band names to be the same).

Because any client device connecting to your network must include the SSID name in the 'I want to connect' request, that any Wi-Fi sniffer can capture and then see.

80 MHz 5 GHz channel 42 is made by combining four 20 MHz channels (only one considered 'primary')

Analogy: A channel is like a lane on an Interstate highway. All cars (AP) can use the same lane (channel), but that is slow and inefficient (lanes go unused). Everything works best when cars (AP) use all lanes (channels) -- as evenly as possible.

Could you put 10 APs in your house and configure them to all use the same SSID and the same channel? Yes, and it would work -- albeit slowly. But that would not be the best and most efficient way to use the available spectrum, since all 10 APs are attempting to use the same 'lane' of a superhighway. Instead, distribute all 10 APs across all available lanes (channels) of the superhighway. Just remember that 2.4 GHz Wi-Fi has overlapping channels and that the only real (non-overlapping) channels available are 1, 6, 11.

Channel Planning: A full discussion on channel planning is beyond the scope of this paper, but in short, always try to leave a full channel of unused spectrum between actively used channels. In other words, if you have a main router on 80 MHz channel 42, never put another nearby AP on 80 MHz channel 58. Instead, you would select a higher channel for the nearby AP. If possible, you want a 'gap' between active channels to avoid Adjacent Channel Interference (ACI). See the appendix on spectral masks [§S] showing the impact of a sideband ACI signal on throughput.

Beware the 'automatic' channel: Some AP/routers improperly set the 2.4 GHz channel to some channel other than one of the three non-overlapping channels. This can be corrected by not using 'automatic' and instead manually selecting either channel 1, 6, or 11.

Another fast DNS service is provided by CloudFlare, with DNS servers 1.1.1.1 and 1.0.0.1.

TIP: And there are many more public DNS servers. Just Google "public dns servers" (google.com).

I actually ran into this 'TTL' problem while at a vacation property. Long story short is that something I depended upon was failing and that I tracked down a problem to the ISP incorrectly caching a DNS entry WAY past the TTL expiration time. When I used the ISP DNS servers, I received an old stale DNS entry. When I used Google's DNS servers, I got a fresh, correct DNS entry. I don't trust ISP DNS servers anymore to 'follow the rules'. They can save money by breaking the TTL rules (caching information longer than allowed).

Xfinity gateway's are the worst! They always seem to be 'wide open' via the HTTP interface (often http://10.0.0.1). The default username and password is admin/password. Are people using the Xfinity app (which requires your account username and password) and unaware that the 'web interface' to their gateway is still wide open using the default username and password?

This chapter assumes that your client device, when right next to a 'modern' router, is capable of good Wi-Fi speeds. If you have an older client device that is not capable of good Wi-Fi speeds, the rest of this chapter won't help you because you first need to upgrade your client device, not the router.

1. Reboot ALL Internet connected devices. First, start with your modem, router, and Wi-Fi network (extenders, AP, mesh, etc) and then wait 5 minutes (for all Wi-Fi bands to be fully operational, especially DFS channels). Next, reboot all other Wi-Fi connected devices (game consoles, smart TV's, tablets, phones, cameras, etc). In some rare cases, this may fix your problem and you are then done.
   
   
2. Check for proper placement [§P] of your existing Wi-Fi devices, especially your main router, and any mesh nodes.

This assumes that your network is capable of fast speeds, but is currently not obtaining fast speeds. If you are not using modern Wi-Fi devices, the gains in speed you can achieve will be minimal.

1. Use Ethernet whenever possible
2. Improve wireless PHY speeds

For any device using Wi-Fi now (smart TV, game console, desktop PC, etc) that has a RJ45 jack, try to switch over to using Ethernet instead of Wi-Fi for that device. Your goal is to free up Wi-Fi for use by devices that can only connect wirelessly.

a) Best v1: Go direct wired: Gigabit ethernet via Cat 5/5e/6/etc is still the gold standard of speed and reliability. If you have a Wi-Fi device that also has ethernet/RJ45 (smart tv, game console, etc), find a way to run a wired Cat 5/6 from your main router to the device. Expect 1000 Mbps PHY and 949 Mbps throughput from 1 Gigabit Ethernet.

TIP: If you are out of ports on your main router, add a Gigabit switch. Be aware that while 1GbE switches are very common, there ARE switches that support 2.5GbE (Cat5e), 5GbE (Cat6), and even 10GbE (Cat6a) speeds. Interesting video (youtube.com) on cheaply adding 10 Gigabit Cat6a/RJ45 to your home network.

TIP: If you don't have Ethernet jacks in your house, investigate if your home's phone jacks were wired using 'structured wiring' techniques -- where Cat5 was run to all phone jack locations and back to a single structured wiring panel. If so, you likely have a golden opportunity to convert some of the unused phone line locations to Ethernet.

b) Best v2: Convert some telephone jacks to Ethernet: It may be possible to convert some telephone jacks to Ethernet [§E9] -- everything depends upon what cable is 'in the walls'.

c) Best v3: MoCA 2.5 Ethernet: If you can't use/run Ethernet wire, but have access to RG6 (CATV) in every room, MoCA adapters [§E5] may be for you. This adds Ethernet, but over existing coax wiring in a home.

d) Fair: Wireless bridge: Many high-end routers can be configured as a 'wireless bridge', meaning that they use wireless to connect to the main router, and provide that Internet to ONLY all of the wired Ethernet LAN ports (does NOT allow for wireless clients). Best when a 4×4 bridge is connected to a 4×4 router. Under good conditions, expect 1500 Mbps PHY and 750 Mbps throughput (Wi-Fi 5).

Yes, you are trading one Wi-Fi (on the device), for another Wi-Fi (on the bridge). But the PHY speed of Wi-Fi on the bridge is (hopefully) several times faster than Wi-Fi on the devices you replaced. Only use this option if PHY speeds go up 2x or more.

Another easy way to do this is to connect your PC wired/Ethernet to a mesh node that has a 4x4 MIMO wireless backbone. You are then likely exchanging your 2x2 wireless for the mesh network's 4x4 wireless backbone, which can double speeds.

e) OK to Bad: Powerline Networking/Ethernet: PLC is a very fast and easy way to obtain slower, but reliable, speeds. See Powerline Networking [§E8].

a) Move as many devices as possible from wireless to wired: Avoid spectrum usage and contention whenever possible (free up TIME on the spectrum). Is there a smart tv that is heavily used for streaming? If so, try to move that to a wired connection, freeing up wireless time for those devices that are forced to be wireless only (like tablets). See this chapter immediately above.

b) Try different channels and TEST: Wi-Fi is a shared resource. If you have neighbors you may actually be sharing spectrum with them. Especially important at night when people come home from work and start streaming.

In reality, selecting the 'right' channel is crazy hard to do (well) -- because a channel with many access points may actually be the 'most unused' channel, if those access points rarely transfer data (vs a channel with one other access point that is transferring data all the time). Often times you just need to change the channel and test (a lot) [§D].

TIP: The non-DFS 5 GHz channels (at 80 MHz, there are only two) are allowed to operate at a higher power level than the DFS channels. You should see better (download) PHY speeds at distance from these non-DFS channels, but everyone (you, neighbors, etc) want to use those channels. Whereas on a DFS channel, you likely will have the channel to yourself.

So try to find an unused DFS channel, which will result in the channel being all yours! A DFS channel is a must if you are in an apartment/condo building (have a lot of close neighbors).

Inexplicably low PHY speeds?: If you see PHY speeds from your client device (when standing right next to your router) that are strangely 'too low', that is a huge tip off that you may be running into some 'interference' -- try changing Wi-Fi channels on the AP/router.

c) Several low-PHY 'heavy' users can significantly slow down everyone else: Devices operating at a very low PHY speed, and using the channel a lot, can slow down an entire Wi-Fi channel. Because what is critical is TIME spent on a channel (which increases as PHY speed decreases). Adding an access point [§18] (and hopefully on a new unique channel), and greatly improving the PHY speed for those devices, can free up time needed by other Wi-Fi clients.

Analogy: Imagine a highway (Wi-Fi channel) where a car (smartphone) is going 5 mph (PHY 65 Mbps) when the speed limit is 55 mph (PHY 866 Mbps). That one car will drastically slow down all other cars (Wi-Fi devices) wanting to use the highway (Wi-Fi channel). Adding a new lane (via AP on new channel) to the road not only puts the slow car (smartphone) onto a new lane (channel), potentially causes the car to all of a sudden start driving 55 mph (PHY 866 Mbps).

d) Get a 4×4 MIMO network adapter: If on a PC with 2×2 MIMO, try using a 4×4 MIMO network adapter (to a 4×4 router). The expectation is that PHY speeds will increase (but not quite double).

But honestly, with a PC, always try to find a way to use Ethernet wired to your main router.

e) Upgrade your client device: If your client device is 1×1 MIMO, get a brand new client device that supports at least 2×2 MIMO. The expectation is that PHY speeds should roughly double (moving from 1×1 MIMO to 2×2 MIMO).

Brand new hardware might help: I have also seen 2×2 MIMO devices made in the last year outperform (consistently stay on a higher PHY speed) than 2×2 MIMO devices that are five years old. This can not be overstated. If you are looking for top speeds, always use modern/new devices. Each generation of newer hardware performs just a little bit better than prior generations.

f) Investigate 160 MHz channels: If your 2×2 client devices support 160 MHz channels (this was rare, but it is becoming a lot more common for Wi-Fi 6), look into a router that also supports 160 MHz channels. This is not always possible, but when possible and there are no DFS channel conflicts (or spectrum conflicts with neighbors), this has the 'potential' to double your PHY speeds (when compared to 80 MHz channels) -- but for only the few devices that actually support 160 MHz channels. But 160 MHz channels require a high SNR (you may need to be very close to the router). Also, remember that wider channels have slightly less range (than smaller channel widths) - details [§J] -- so this works best when very close to the router/AP.

g) Reserve 5 GHz for true 802.11ac devices: A requirement of any device being able to call itself 802.11ac capable is that it must support 80 MHz channels in 5 GHz. However, dual-band 802.11n devices can see your 5 GHz SSID and connect to it using 20 MHz (or 40 MHz) channels. If that 802.11n device is a heavy Internet user, this could slow down all of your 80 MHz channel devices. Move that problem device to the 2.4 GHz band SSID. This frees up time on the much faster 80 MHz 802.11ac channel for 80 MHz capable devices.

Analogy: A 802.11n device operating at 20 MHz in 5 GHz is like a car using one lane of a four lane Interstate and simultaneously preventing the three other lanes beside it from being used (most devices operating in 5 GHz want to use 80 MHz channels).

But if the dual-band 802.11n device is a lightweight when it comes to Wi-Fi usage, then keep it on 5 GHz, as it is 'doing no harm'.

It is all a balancing act -- because if the 802.11n device does not work properly in 2.4 GHz (too slow or unreliable due to congestion) then you may need to keep the device in 5 GHz (eg: a Ring camera, where reliable video is critical).

h) Update firmware: (1) Make sure that your router/AP is running the latest firmware. It is rare, but there have been times that a performance problem is found and corrected and new firmware is released that fixes the problem For example, this WAN to LAN performance bug (duckware.com). (2) And if on a Windows laptop, check for any updates to the Wi-Fi drivers.

i) Switch Wi-Fi bands: Often times (but not always), PHY speed increases dramatically when there is a switch from 2.4 GHz to 5 GHz. This is because the SINR for 5 GHz is often much better than the SINR in 2.4 GHz. This improved SINR together with wider channels (20 MHz to 80 MHz) often results is a big speed improvement. Confirm that your dual-band device is connecting to 5 GHz and using 80 MHz channels. If not, consider upgrading your client device and/or router.

Analyze your client devices that download/upload the most data. They should be running at high PHY speeds [§4]; and if not, fix by moving devices around, or by adding an access point [§18].

A typical Wi-Fi range extender

★ A GREAT way to see first hand 'what is wrong' with Wi-Fi extenders is install one where it is NOT needed like right next to your main router, connect to the extender, and observe Wi-Fi throughput speeds cut in half or much worse.

Don't confuse great signal (at range) -- that a Wi-Fi extender does give you -- with great speed (at that range). Just because you used a Wi-Fi extender and get a great signal 'at range' does not mean that you now have great speed at that extended range.

Instead, you likely traded a more reliable signal for a slow speed (because there is still the 'extender to main router' path that packets must traverse) -- which in some edge cases, is a good tradeoff to make (sometimes a slow connection is better than no connection).

Many extenders 'on paper' are a 'zero-sum game'. Because they are (typically) located in the middle between the main router and a client device, they improve the signal strength between the two paths (extender to router and extender to client device) only enough to make up for doubling Wi-Fi utilization (packet transmitted twice), and no more. Packets are (often) re-transmitted on the same channel, band, and channel width. So not much (if anything) is gained speed wise other than possibly a more reliable (but slow) Wi-Fi path.

★ Where extenders may actually work and help a little bit is if the device connecting to the extender is using slow Wi-Fi 4, but the extender backhaul to the main router is using faster Wi-Fi 5. Especially when the extender implements a MIMO level (eg: 2×2) that is higher then the device you are trying to extend (eg: 1×1).

Also, sometimes extenders can help to 'bend' a Wi-Fi signal around a major physical obstruction (eg: elevator shaft).

But in all cases, if an extender helps a little, then a mesh network would work even better.

Namely, if you are standing right next to the Wi-Fi extender, the PHY speed will be fantastic, but remember that there is still a hidden PHY speed between the extender and main router that you can't see that comes into play and limits throughput.

So the huge advantage that a wired/Ethernet Access Point has over Range Extenders (and mesh networks with a wireless backhaul) is that (1) packets are only transmitted ONCE over Wi-Fi AND that (2) the AP can be placed exactly where needed most so that client devices near that AP now get maximum Wi-Fi speeds (no more need to place extender devices 'mid-way')!

Mesh networks DO also re-transmit packets, but they (virtually always) use a 'backhaul' channel/band/width that (1) is often different than the main channel and (2) much faster than the main channel (high end mesh networks use 4×4 MIMO for the backhaul). A huge bonus is if you can find a way to wire each mesh node back to the main mesh node/router via 2.5 Gigabit Ethernet (try to avoid using a wireless backhaul).

For example: With two PHY links, each at 28.88, acting as one link, the effective PHY is 1/(1/28.88+1/28.88), or 14.44. The SAME as transmitting one packet once at 14.44 Mbps, but hopefully more reliably. Using a 'same channel' extender is often a zero-sum game, that just consumes Wi-Fi bandwidth.

Example: Using the example above, the overall path speed increases to the minimum of 28.88 (no channel contention). And because Wi-Fi 5 PHY speeds are so much better than Wi-Fi 4, we can move the extender even closer to the Wi-Fi 4 client device (max PHY 72.22), and increase the PHY speeds even more.

• Consumer Reports: "Should you buy a Wi-Fi Range Extender" (consumerreports.org)
• Techquickie: DON'T Buy A Wi-Fi Range Extender! (youtube.com)
• CNET: "Mesh Wi-Fi vs. range extenders: The best option for your home" (CNET on youtube.com)

TIP / Use a router: There are dedicated 'access points' that you can buy, but it is often much easier to just buy a normal recommended [§21] router (or re-use an old router) and configure it in 'Access Point' mode -- so that 'Router' functionality is disabled (as that is still handled by your main router), while keeping the 'wireless' AP functionality (and LAN Ethernet ports) intact.

♲

Also, using a 'router as an Access Point' is a great way to recycle and re-use older routers when the main router is upgraded.

A good way to think of an 'access point' is that it is a same as connecting an Ethernet cable to your client device -- you are just connecting to Ethernet wirelessly via the AP.

How to connect a new 'Access Point' to your Main Router -- green lines are Ethernet cables

• TP-Link: How to configure the TP-Link wireless router as Access Point (tp-link.com)
• Netgear: How do I change my NETGEAR router to AP mode? (netgear.com)
• Asus: How to set up access point mode? (asus.com)
• Linksys: How to use a Linksys router as an Access Point (linksys.com)
• Wavlink: How to set up WAVLINK router to AP(Access point) mode? (wavlink.com)
• Eero: How to change the Eero router to AP mode (eero.com)
• Tenda: How to change a Tenda router to AP mode (bitdefender.com)

Configuring a TP-Link "Router" as an "Access Point"

But let's also be realistic -- Wi-Fi speeds maxing out at 1 Gbps is a very good problem to have. The solution is a main router with all LAN ports at 2.5 Gbps (or higher).

You can name access points uniquely if you want to, but then all of those SSID show up in Wi-Fi lists on client devices (creates a lot of name pollution).

The only time I have used a unique SSID name for an access point is when I added an AP (on a unique channel) dedicated to service a single wireless Ring camera, and I wanted only the camera -- and no other clients in the home -- using that access point.

• For 2.4 GHz, only use non-overlapping channels 1, 6, or 11.
• For 5 GHz, only use channels that fall into different 80 MHz channels (for example, 36, 40, 44, 48 are all in the same 80 MHz channel). Also, try using DFS channels first.
• For 6 GHz, only use channels that fall into different 160 MHz channels.

For example, your 'main router' is in your living room, but you then also have an access point (wired/Ethernet back to your main router) in your home office.

In your office, you will get the fastest Wi-Fi speeds that are possible for your client devices, and because there is Ethernet back to the main router, packets are never re-transmitted twice (as they would be with extenders or mesh).

TIP: What Ethernet port should be used (on a router configured as an access point) to wire/Ethernet the 'access point' back to your wired network -- the WAN port or a LAN port? Technically, it should not matter at all -- as every port 'should' work equally well. However, be aware that some routers (especially older ones) do have some bugs in properly routing ALL packets across the WAN to LAN interface (when the router is in AP mode). So, AFTER configuring a router in "Access Point Mode", consider switching the Ethernet cable from the WAN port on the AP to a LAN port on the AP (and no longer use the WAN port).

At one house, I added an access point into the 'kids playroom' -- so that any streaming or game play in (or near) that room will go through that access point (and not impact Wi-Fi in the rest of the house). Plus, everyone in the kids playroom obtains maximum PHY speeds, which results in the fastest Wi-Fi speeds possible.

The kids can max out their Wi-Fi channel (to 100%) without impacting Wi-Fi speeds for any other users in the rest of the house.

• TP-Link: tplinkwifi.net
• Asus: www.asusrouter.com
• Netgear: routerlogin.net
• Tenda: tendawifi.com

WARNING: But 'ping' these names from a Command Prompt window to 'find' the IP Address. If you type these names into Chrome (to access the router's web interface), that may FAIL. You may NOT get the correct name resolved if Chrome is using 'secure DNS', which bypasses normal DNS (where a router maps these special names to itself).

Access Point on non-overlapping 5 GHz channel 58 -- Main Router on 5 GHz channel 122

The significant advantage this 'Access Point' configuration has over many 'Mesh' systems is that there is NO overlap in Wi-Fi channel usage between the 'INET' and 'AP' nodes on any band, meaning that both nodes operate 100% independently -- both nodes can Tx/Rx at the exact same time (whereas for many mesh systems, only one node can be active at a time, because mesh nodes use the same channels).

• a more expensive 'premium' product to fully support the throughput requirement
• a 'controller' (or cloud service rental) to manage the business AP's -- and higher end business AP's require a controller
• multiple PoE switches or adapters to power the business AP's and/or regular switches

Wi-Fi EasyMesh -- Wi-Fi Alliance

Mesh networks often are only 2×2 MIMO for the backhaul and 2×2 MIMO to client devices. And if 4×4 MIMO is supported, most often that is only for the backhaul, with client device communication still only at 2×2 MIMO.

"An access point always delivers better performance than a wireless mesh satellite of the same Wi-Fi grade." -- from Dong Knows Tech (dongknows.com).

A wired/Ethernet Access Point will ALWAYS have a significant guaranteed performance advantage over a wireless mesh network. Why? Because mesh satellite nodes: (1) transmit every packet twice (or more) wirelessly, and (2) all use the SAME backhaul channel, creating a bottleneck when multiple mesh nodes actively need to use Wi-Fi at the same time.

	Asus ZenWiFi AX XT8 -- Wi-Fi 6 (2.5 Gbps WAN; 4×4 backhaul) $550 AX6600 -- 2.4GHz 2×2 574 Mbps (40 MHz) -- 5GHz-1 2×2 1200 Mbps (80 MHz) -- 5GHz-2 4×4 4800 Mbps (160 MHz) specs
	Netgear Orbi RBK853 -- Wi-Fi 6 (2.5 Gbps WAN; 4×4 backhaul) $800 AX6000 -- 2.4GHz 4×4 1147 Mbps (40 MHz) -- 5GHz-1 4×4 2400 Mbps (80 MHz) -- 5GHz-2 4×4 2400 Mbps (80 MHz) specs

	Amazon Eero Pro 6E -- Wi-Fi 6E (2.5 Gbps WAN; 2×2 backhaul) $549 AXE5400 -- 2.4GHz 2×2 574 Mbps (40 MHz) -- 5GHz 2×2 2400 Mbps (80 MHz) -- 6GHz 2×2 2400 Mbps (80 MHz) specs
	Google Nest WiFi Pro -- Wi-Fi 6E (1 Gbps WAN; 2×2 backhaul) $320 AXE5400 -- 2.4GHz 2×2 574 Mbps (40 MHz) -- 5GHz 2×2 2400 Mbps (80 MHz) -- 6GHz 2×2 2400 Mbps (80 MHz) specs
	Linksys MX8503 Atlas -- Wi-Fi 6E (5 Gbps WAN; 4×4 backhaul) $400 AXE8400 -- 2.4GHz 4×4 1147 Mbps (40 MHz) -- 5GHz 4×4 2400 Mbps (80 MHz) -- 6GHz 4×4 4800 Mbps (160 MHz) specs
	TP-Link Deco X75 Pro -- Wi-Fi 6E (2.5 Gbps WAN; 2×2 backhaul) $400 AXE5400 -- 2.4GHz 2×2 574 Mbps (40 MHz) -- 5GHz 2×2 2400 Mbps (80 MHz) -- 6GHz 2×2 2400 Mbps (80 MHz) specs

But unlike Wi-Fi extenders [§17] (which typically operate on the same channel as the main router), 'better' mesh networks often operate the wireless 'backhaul' on a different Wi-Fi channel (and often a different Wi-Fi band), which results in mesh networks being much faster then Wi-Fi extenders.

However, notice what happens when multiple mesh nodes all need to use the wireless backhaul network all at the same time -- they must do so serially. And very likely at speeds well below Ethernet speeds.

This is why a wired/Ethernet backhaul is greatly preferred (faster and operates concurrently) over a wireless backhaul. You just can't beat the speed of a dedicated copper wire.

WARNING: Watch out for inexpensive 'Mesh' systems with only two Wi-Fi bands and NO backhaul. They claim to be 'Mesh', but without a fast dedicated wireless backhaul in place, these mesh systems are little more than just expensive Wi-Fi extenders!

Mesh can be VERY expensive

Also, some mesh systems use "proactive 802.11k/v client steering" that cause client devices to switch to a different mesh node before a client would normally decide by itself to switch mesh nodes.

Analogy: Using the same channel for everything is like building a six-lane highway but then forcing all cars to SHARE just a single lane -- is very inefficient! Instead, it makes a lot more sense in capacity and throughput to use access points, where each AP is operating 100% independently -- on a unique non-overlapping front-haul Wi-Fi channel AND using a wired backhaul.

And even if your mesh system does have a dedicated 'backhaul' channel different than the 'front-haul' channel (not all mesh do), there is still only a single backhaul channel that all mesh satellite nodes must still share. And on a busy network, that means contention.

TIP: Use wired/Ethernet backhaul with Mesh whenever possible: The better mesh networks add an Ethernet jack on satellite mesh nodes, which allows for a wired/Ethernet backhaul. So, whenever possible, plug mesh network devices into an Ethernet network (wired/Ethernet back to the primary mesh node).

Every 'front-haul' AP node is on a unique channel, and the 'back-haul' is Ethernet. AP's never compete with each other for wireless spectrum.

Admittedly, running Ethernet cable is not always possible or cost effective (may need to pay someone else to install it). But, it is cost effective for me because I am willing to do all of the installation work myself. For me, this maximizes Wi-Fi speeds (performance) and minimizes costs.

Regarding this WSJ article and Eero: I also have measured poor Wi-Fi performance with Eero and also find it unacceptable that even basic Wi-Fi settings (like channel number or SSID name per band) can NOT be changed in an Eero.

Look for mesh network systems that support EasyMesh. Avoid mesh systems that refuse to support EasyMesh.

• Compare Eero models (eero.com) -- "Radio Frequency" section lists MIMO level for each band
• More details on Eero (eero.com)

Router manufacturers' wireless speed claims are just like a used car salesman trying to convince you that a Formula 1 racecar will reduce the time of your morning commute to work. But what really matters more is the actual speed you can achieve for the roads you are driving on (your client device), NOT the 'maximum' potential vehicle speed (the router).

But as soon as you plug a PC into gigabit Ethernet and connect to your router, yes, you will easily obtain 1 Gbps speeds (technically, 949 Mbps throughput, max) -- and get what you are paying for.

I have been in several vacation rental properties where the owner brags that they have Gigabit Internet, only to arrive at the property and discover that Wi-Fi throughput is around 200 to 400 Mbps (because the main router, with Wi-Fi, is located several rooms away from the main living area, or is too far away from the provided work desk). The only way to get reliable Gigabit throughput wirelessly is to be very close to an AP (plus it helps to have a router and client device that both support 160 MHz channels). OR, the owner is paying for 1 Gbps Internet, but then only has a Comcast XB6 gateway with maximum Wi-Fi throughput right next to the router around 700 Mbps (again, the weakest link in the chain is the speed you get).

And frankly, it is actually pretty hard for most people to notice any speed difference between 100 Mbps and 1 Gbps for 'typical' Internet usage (email, web browsing, streaming, etc). Of course, if you are downloading a huge file you will notice, but for what most people use the Internet for, they simply won't notice the speed difference.

And of course, PHY speed only indicates potential speed. You should then run throughput speed tests [§D] to confirm that the Wi-Fi channel performs well (not sharing bandwidth with others, or experiencing interference).

Other crazy examples of this (from the past) are the Netgear R6120 (netgear.com), Linksys E5400 (linksys.com), and TP-Link Archer A54 (tp-link.com) -- all with advertised wireless speeds "up to 1200 Mbps". However, ALL Ethernet ports (both LAN and WAN ports!) are only Fast Ethernet -- meaning 100 Mbps maximum speed to/from the LAN and to/from the Internet.

Notice that many higher end Wi-Fi 6/6E/7 routers now offer 2.5 Gbps (or higher) WAN ports.

The main reason for using only 20 MHz channels is that businesses often install a bunch of access points, and need each AP operating on a unique channel, that is not too close in frequency to that used by a neighboring access point. Otherwise, performance would tank with too much adjacent channel interference. And in 5 GHz there are simply not enough 80 MHz or 40 MHz channels to effectivity provide separation. But there are enough 20 MHz channels.

Ethernet all of a sudden looks pretty cool when every smart TV in the house can RELIABLY stream 4K at the same time because NO Wi-Fi is being used!

Also note that most (all?) HDTV's have only a Fast Ethernet (10/100) port, and not Gigabit, as a cost savings measure -- since 100 Mbps is more than 'fast enough' for 4K streaming.

R7800 to Galaxy S6 long range

This observation was confirmed by using the MCS Spy tool (duckware.com), which shows that clients are often transmitting (to the AP/router) at lower MCS levels (Rx MCS seen right) than the AP/router (Tx MCS seen right) is transmitting to the client.

Have you ever tried to connect to a weak Wi-Fi network, only to have your client device complain that it failed to connect? And then you wonder, 'but my device can clearly see the Wi-Fi network name, so why is a connect failing'? You move slightly closer to the AP/router and your device connects? This is almost certainly caused by the client transmitting at lower power levels than the AP/router (is transmitting).

TIP: The same principle applies to large homes, where you want everyone evenly connected to several different AP's, not everyone connected to one AP. When each AP is on its own unique (and non-overlapping) Wi-Fi channel, this 'creates' more bandwidth (as unique Wi-Fi channels all operate independently and concurrently).

Unrealistic test setup

Online reviews often do demonstrate 'maximum' router capabilities. But you may experience something different with your client devices. If you want those fast speeds, now you know how to obtain them -- with the router, or an access point [§18] installed right next to you.

And it even goes further. For example, Qualcomm makes 'reference designs' (actual working products), allowing other companies (like Netgear) to then use the reference designs to make their own routers. An example of this is the Netgear Nighthawk R7800, which is just a "Qualcomm Atheros AP161 reference board".

But also, each new wave/generation of hardware/chips does seem to perform just a little bit better than prior generations. So sometimes, just being 'newer' can be better.

• MIMO: 2x (2×2 MIMO [§7]) or 4x (4×4 MIMO)
• Increased channel width: over 2x (HT40), over 4x (VHT80), over 8x (HE160), or over 16x (EHT320)
• Higher MCS levels: 2x (Wi-Fi 4 to Wi-Fi 6, due to higher QAM encoding)

Throughput to Main Router one room away - GOOD

Throughput to AP in the same room- GREAT

• You get the fastest Wi-Fi PHY speeds possible (real throughput) - directly benefiting you
• This frees up TIME on the channel for all other Wi-Fi devices - indirectly benefiting everyone else

• higher QAM encodings like 1024-QAM and 4096-QAM
• wider channel widths [§J]

For example, you may easily obtain QAM-1024 data rates (because you experience a low noise floor), but your friend with the same setup (but at a different location) may never get QAM-1024 data rates (because they experience a high noise floor) due to adjacent channel interference [§P], or some other factor.

The spectrum usage all around you (from ALL of your neighbors) from Wi-Fi, and other sources, will impact how you perceive and experience Wi-Fi at your location. Don't assume that everyone else experiences Wi-Fi the same way that you experience it.

When updating a router, verify that client device PHY speeds (and throughput speed tests) actually increase, especially for devices 'at range'.

For example, if you have high-end Wi-Fi 6 client devices supporting HE160 and upgrade your VHT80 Wi-Fi 5 router to an HE160 Wi-Fi 6 router (like those recommended below), I would expect to see maximum PHY speeds increase from 866 Mbps to 2400 Mbps and over 1 Gbps throughput (standing right next to the router), and then only modest speed increases over Wi-Fi 5 'at distance'. Warning: Apple Mac/iPhone/iPad client devices don't support HE160 in Wi-Fi 6 in the 5 GHz band!

• 4×4 MIMO - increases signal quality, reliability, and range for all 2×2 MIMO client devices. Do not buy a 2×2 or 3×3 MIMO router. You really do want a 4×4 router.
• DFS channels - you need a router that supports ALL 5 GHz 80 MHz DFS channels, to increase the likelihood of NOT sharing a channel (and therefore bandwidth) with a neighbor, and needed for 160 MHz channel support.
• HE160 (160 MHz channels) - you need a router that supports HE160, because support for 160 MHz channels in Wi-Fi 6 client devices is now becoming very common (so you want to take advantage of that).
• Multi-Gigabit Ethernet - you want a router with a multi-gigabit WAN port (eg: 2.5 Gbps, or higher). If your Internet speeds are not above 1 Gbps, then a 1 Gbps WAN port is just fine (and expect max throughput around 949 Mbps).
• A mid-range Wi-Fi 6 (802.11ax) router - this is the best VALUE today (September 2024) -- expect to spend 'around' $200 plus/minus $50. Avoid routers below $150 and above $300.
• beamforming - improves signal strength, which increases the range at which devices stay at fast speed -- should be a standard feature of any new mid-range Wi-Fi 6 router.
• Access Point Mode - look for a router that supports "access point mode" (most routers will). Because when you do upgrade to a newer version of Wi-Fi years from now, you may want to reuse the old router as an 'AP' in your new network (and not have the old router sit on a shelf unused).
• Wi-Fi Certified - not absolutely required, but if the router is certified, this guarantees "interoperability, security, and reliability." Product Search. Also, watch out for routers certified to a lower specification than expected (eg: a 802.11ax router certified for only 802.11ac is a red flag).

Also, it is easy to find these criteria in high-end (rather expensive) routers, but the challenge is to find that combination in an affordable mid-range router!

And don't forget to keep an eye out for clickable 'coupons' (example seen right) on Amazon product pages. You do NOT get the discount unless you click on the coupon.

Best ($150-$230)	Best ($220-$300)	Good ($150-$250)
TP-Link Archer AX80 ✓ WAN: 2.5 Gbps Ethernet ✓ Max Throughput: 1.8+ Gbps ✓ 2.4 GHz: 4×4 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels ✓ HE160 Now $150 -- 35% off	Asus RT-AX88U Pro ✓ WAN: 2.5 Gbps Ethernet ✓ Max Throughput: 1.6+ Gbps ✓ 2.4 GHz: 4×4 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels ✓ HE160	Netgear Nighthawk RAX50 WAN: 1.0 Gbps Ethernet Max Throughput: 949 Mbps 2.4 GHz: 2×2 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels ✓ HE160

TP-Link Archer AXE75 2×2 MIMO

However, there is an 'honorable mention' -- the TP-Link Archer AXE75 (amazon.com) (seen right) deserves to be pointed out. It is an entry-level Wi-Fi 6E router supporting ALL three Wi-Fi bands (2.4 GHz, 5 GHz, and 6 GHz), 160 MHz channels (HE160), and DFS channels. And of note is that it only has 1 Gbps WAN+LAN ports (not 2.5 Gbps). This router is not a recommendation ONLY because the router is missing 4×4 MIMO (it has 2×2 MIMO).

However, let's also be very realistic. If you have less than 1 Gbps Internet and don't need extended range (or if you do, are willing to install as a main router and as an access point elsewhere where needed), then this router, at around $180, is actually a FANTASTIC value, due to support for all three Wi-Fi bands (2.4 GHz, 5 GHz, 6 GHz).

Another 'honorable mention' is the TP Link Archer AXE95, but availability is limited. It is very similar to the AXE75 above, but adds (1) 4×4 to only the 5 GHz band (other bands remain 2×2), and (2) a 2.5 Gbps WAN port.

TP-Link BE550 2×2 MIMO

The 2.5 Gbps ports are a huge added bonus -- because for most people, there will now be no additional expense in buying an external 2.5 Gbps switch. The four 2.5 Gbps LAN are enough for connecting a desktop computer and an access point (or two).

Plus, you actually don't want everyone in a larger home connected to a single router/AP channel. Instead, you want multiple access points, with each AP operating on a different Wi-Fi channel. The result is that traffic to each AP can happen concurrently (instead of serially as it would be to a single router). In effect, you have increased Wi-Fi capacity.

Most people will obtain FASTER network throughput via a 'recommended' router in the same room as they are in (configured as an access point and wired/Ethernet back to a main router) than they will from an expensive $600 main router one room away!

Analogy: An expensive router is like a Ferrari. When your family needs transportation, do you buy one Ferrari for the whole family to use (share), or do you buy several other vehicles for everyone to use (independently) -- for the same price?

I prefer wired/Ethernet backhauls as they can quite simply be much faster than a Mesh systems wireless backhaul. When multiple users are all using Wi-Fi at the same time (each to their own AP), wired/Ethernet backhauls from multiple access points can all operate concurrently (in parallel). But a mesh wireless backhaul is a shared medium (between mesh nodes), so concurrent traffic must be serialized (and is slower).

Most people will obtain FASTER network throughput via a 'recommended' router in the same room as they are in (configured as an access point and wired/Ethernet back to a main router) than they will from an expensive $900 mesh Wi-Fi node one room away!

However, mesh networks can be incredibly convenient (just plug in and go), and if you want to go down that path, see Mesh Wi-Fi Network Systems [§19].

Analogy: Going back to the transportation analogy, mesh networks are like sharing a taxi with someone else -- you will definitely get to your destination, but there may be an intermediate stop (mesh node). Not as fast as having your own vehicle and taking a direct route (using an AP).

TP-Link Archer AX21 2×2 MIMO

Also, don't expect top notch performance (throughput) from some cheap routers. While Wi-Fi specifications may be seem similar, run a speed test [§D], and throughput results can be disappointing.

Honorable mention: It is interesting to point out that the "#1 Best Seller" router on Amazon.com is only an entry level TP-Link AX21 (amazon.com) for 'around' $75, but with only 80-MHz channels, 2×2 MIMO, and no DFS channel support and yet does seem to get decent speed test results up to 800 Mbps (highspeedinternet.com) from client devices.

But let's also be practical. If you lower throughput expectations (or can't spend hundreds), or you don't need a 'whole house' router, then even a $28 entry level router configured as an access point and wired/Ethernet back to your main router, installed in a single room, to provide Wi-Fi only in that one room (like for a kids play room), should be able to provide at least 230 Mbps (and possibly much higher; depends upon router) Wi-Fi connectivity to client devices. Not great, but also not bad for $28. Source (duckware.com).

Analogy: Going back to the transportation analogy, buying an very low end router is like buying a moped. It works, providing you with slower basic transportation, but don't expect it to have all the speed and features of a car.

For example, place the main router some place centrally located in the house -- and then add an access point (wired/Ethernet to the main router) in your home office.

TIP: Don't forget to look into 'Enterprise' grade Access Points. Ubiquiti sells a line of 4×4 access point products that DO support ALL 5 GHz channels, and are very reasonably priced. For example, the UniFi 6 Pro which is a 4×4 Wi-Fi 6 AP.

TIP: The hidden YEARLY cost of electricity [§E4] for 24x7 'always on' devices can really add up.

One example: Compare Netgear's R7800 (router) to the C7800 (router + cable modem). With the R7800, you have full control over firmware updates. But with the C7800, you have NO control and Netgear states "Firmware upgrades are pushed down by your ISP". But if your ISP is a small regional player, you might get NO firmware updates at all. Or what if the ISP pushes new FW to your combo device and you run into a problem -- It is then impossible to revert FW.

Worse yet is that some ISP's refuse to push any new firmware to customer owned cable modems! I know this from first hand experience with Spectrum outside of Orlando FL. I bought a Netgear CM1000V2 and noticed that it was still on V1.0 firmware. I contacted Spectrum and they refused to do anything about it since the modem is 'customer owned' (and they then emphasized that I should be using their modem instead).

Newer hardware is demonstratable better than older hardware (youtube.com).

"Broadcom's RangeBoost technology provides up to 9 dB of receiver sensitivity improvement by utilizing advanced signal processing techniques coupled with unique receiver architecture .... will benefit from an expanded coverage area" -- Source (broadcom.com).

You want 'full bars'

• use a Wi-Fi 6 or later router
• use Wi-Fi 6 or later client devices
• be as close to the router/AP as possible -- you want 'full bars'
• have the fewest obstacles walls, floors, etc possible between client+router

• Use modern devices -- older devices may not have the 'horsepower' to sustain high throughput
• In Wi-Fi 5, the only way to obtain 1 Gbps throughput is via 160 Mhz channels, which most client devices do not support and if supported, you need to be very close to the router.
• In Wi-Fi 6, you CAN obtain 1 Gbps throughput via an 80 MHz channel in 5 GHz, but you need great signal strength topmost 1201 PHY speed, by being very close to the router.
• But you WANT to use 160 MHz channels instead of 80 MHz channels in 5 GHz because requires DFS channel support that will extend the range at which you can successfully obtain 1 Gbps throughput. But Apple devices do not support HE160 in 5 GHz.
• But using 160 MHz channels in 5 GHz (there are only two) could either (1) work just fine, or (2) be impossible -- due to potential DFS channel conflicts.
• Due to this DFS channel uncertainty, using Wi-Fi 6E (6 GHz band) is much better (can always use 160 MHz channels), but only if you are close to your router, and both client+router must fully supports Wi-Fi 6E. Also, Wi-Fi 6E routers (with all the features you really want) can be very expensive AND range of 6 GHz channels is reduced as compared to 5 GHz channels.
• And in all cases above, you WANT a 4×4 MIMO router (instead of 2×2 MIMO), as that helps to to extend the range at which you can successfully obtain 1 Gbps throughput.

TP-Link BE550 (Wi-Fi 7)

And then of course, with increasing distance and obstacles, Wi-Fi speeds will decrease quickly. Add Wi-Fi 6E access points [§18], wired/Ethernet back to the main router, where needed to again guarantee 1 Gbps speeds.

Wi-Fi 6: You can use a Wi-Fi 6 router and 160 MHz 5 GHz channels to obtain 1 Gbps speeds, but since DFS channels are then used, there is a risk that the router will 'kick you off' the DFS channel, resulting in the router reverting to an non-DFS 80 MHz channel. For Wi-Fi 6 80 MHz channels, you CAN still get 1 Gbps throughput, but only when very close to the router/AP, and most likely not through any obstacles (expect only 700+ Mbps one room away).

Stick your toes into Wi-Fi 7 waters?: The TP-Link BE550 (amazon.com), seen right, is a Wi-Fi 7 router, and stands out from all its competitors due to the value price of $220 to $250. Virtually all other Wi-Fi 7 routers start out at around double that. The BE550 is only 2×2 MIMO, has Wi-Fi 6E built-in, and comes with Wi-Fi 7 MLO (5 GHz+6Ghz) for future Wi-Fi 7 clients.

And adding a Wi-Fi 6 access point [§18] wired/Ethernet back to the main router, can guarantee 1 Gbps Wi-Fi throughput somewhere else in the house.

Why I keep pushing 4×4 MIMO: My personal experience over many years of testing is that 4×4 MIMO routers 'at range' regularly outperform 2×2 MIMO routers. For example, I have a test setup going 40 feet through three walls, a closet full of stuff, and a major obstacle (HVAC air handler), where Wi-Fi throughput in 5 GHz (160 MHz channel) can either be 300 Mbps (a 2×2 MIMO AP), or 600 Mbps (a 4×4 MIMO AP).

Cat 5e - notice twists?

Why is it called 'twisted pair': Because each pair of wires is actually 'twisted' to help to reduce noise / interference, and each pair in a cable twisted at a different rate (twists per inch) to help reduce crosstalk between the pairs of wires in a cable. Very noticeable when you compare the orange to brown twisted pairs in the photo (upper right).

And the number of 'twists per inch' for Cat 6 is noticeably even way higher than in Cat 5e.

See also more information (wikipedia.org) and interesting demonstration video (youtube.com) on why twisting helps.

Interesting Fact: What does "TP" in TP-Link mean? Answer (wikipedia.org)

Cat5e cable can be used up to 100 meters (328 feet) for all Ethernet speeds up to (and including) 5 Gbps. It is only when you get to 10 Gbps that you need to think about higher quality Cat6a cable. But Cat5e can still work for 10 Gbps distance up to around 100 feet. Anything past that and you definitely need to switch to Cat6a.

Also, the quality of the cable, and the quality of 'termination' matters a LOT. There is a right way to terminate cables and a wrong way, and a LOT of what I find on youtube is the wrong way! The bottom of this section has links to several trueCable videos on the right way to terminate cables.

1. 802.3af / 802.3at standards: Very common. These are industry standards (fully plug/play). See Wikipedia. 802.3af allows for a maximum of 15.4 watts and 802.3at (aka PoE+) allows for a maximum of 25.5 watts. And there is a new recent PoE++ that can deliver even more power. The advantage of these standards is that the devices 'negotiate' the amount of power needed and delivered. No harm is done if plugged into a device not expecting power (as the power is negotiated).
2. Passive PoE 1 Gbps: This is 'relatively' new. Kind of 'in the middle' between standards above and passive below. All pins send data, to achieve 1 Gbps, and some pins also send power (not negotiated). Expect damage if plugged into a device not expecting power.
3. Passive PoE 100 Mbps: This was very common years ago, but not so much anymore given the 802.3af/at standards now exist. Ethernet was on pairs 1/2 + 3/6 and power was delivered over pair 4/5 + 7/8. Expect damage if plugged into a device not expecting power.
4. Proprietary: In some very old PoE equipment you will find proprietary methods of sending Ethernet and power over the 8 pins. Expect damage if plugged into a device not expecting power.

Example: A 802.3at PoE switch, to adapter (seen right), to 1000' coax, to adapter (seen right), to 'PoE powered switch', to two Ring PoE cameras -- all powered by a single PoE switch port at the source (no electrical power available along the path nor at the destination).

TIP: Do not confuse EOC with MoCA -- these are two completely different technologies.

Comparing CCA to solid wire

It is all about money. Aluminum is 'cheap' compared to copper (copper costs 4× more than aluminum).

So a price too good to be true for cable is a big tip off. All 'CCA' wire is relatively inexpensive. All 100% copper wire is noticeably more expensive -- and labeled as such to explain the increased price.

The Cat 6 specification actually requires conductors to be pure copper (wikipedia.org).

• Ethernet cables explained (eaton.com) - TONS is great information on cable types
• Understanding Ethernet Wiring (practicalnetworking.net)
• CMP (plenum) vs. CMR (riser) CAT cable (lanshack.com)
• Looking at 2.5 and 5 GbE (nextgigsystems.com) - where increasing GbE speeds are coming from

UbiGear Ethernet Network kit

• a crimper for RJ45 ends, blue handle
• RJ45 ends works for both solid and stranded cable
• a punch down tool for keystone jacks, yellow
• a cable testing tool tests pin to pin connectivity, green

For example, if you wire a cable (incorrectly) so that the twisted pairs are on 1/2, 3/4, 5/6, and 7/8 -- then when Ethernet sends a signal down pins 3/6 (which it expects is a single twisted pair), that signal is now inappropriately 'split' and travels down individual wires in two twisted pairs (instead of two wires of a single twisted pair).

Cat 5/5e RJ45 - wires in a single row

Cat 6/6a RJ45 - wires in staggered rows

If not, verify that the 'teeth' on your crimp tool are properly interleaving with the RJ45 connector (wiisfi.com).

• an unshielded punch down keystone jack (truecable.com)
• a Cat6-6A unshielded RJ45 connector -- with load bar (truecable.com)
• a shielded Cat6-6A RJ45 connector (truecable.com)
• How untwisting CAT cable too far can reduce Ethernet speeds (youtube.com)
• Residential Bonding and Grounding of Shielded Ethernet Cable (youtube.com)

• Episode 1 - Low-voltage best practices Q&A
• Episode 2 - A keystone jack Q&A
• Episode 3 - A breakdown of all ethernet cable jacket types
• Episode 4 - Everything to know about RG6 coaxial cable
• Episode 5 - Network installation horror stories
• Episode 6 - Are you terminating your Ethernet cable wrong?
• Episode 7 - How to get into the low-voltage industry
• Episode 8 - Is cheap Ethernet cable safe to use?

• Download (at the ISP): When your internet connection starts multiple downloads (like, multiple people using the Internet), buffering takes place within the ISP network (which holds packets to enforce your Internet download speed). The ISP must implement Bufferbloat mitigations.
• Upload (at your Modem): When you transmit/upload to the Internet faster than your Internet connection speed, packets buffer. In cable modems, DOCSIS 3.1 implements mitigations, that regardless of router used, will solve Bufferbloat for most people. So if you only have a DOCSIS 3.0 (or earlier) cable modem, strongly consider upgrading to a DOCSIS 3.1 modem.

LAN/Phone Structured Wiring Cabinet Gray Cat5e = 4-line Phone / room Gray Cat5e = spare Cat5e / room Blue Cat5e = LAN1+Internet / room Yellow Cat5e = LAN2+Internet / room Red Cat5e = Thermostats (not used) Orange = Modem/Router Internet CATV Structured Wiring Cabinet Black RG6 = CATV / room White RG6 = spare RG6 / room Red Cat5e = Internet to each TV

KEY Wi-Fi concept: Install and use wired/Ethernet connections whenever possible. Only use Wi-Fi when that is the only connectivity option.

When I built a new home in 2005-2006, my builder tried to convince me that installing Cat5e everywhere was not needed because everything was going 'wireless'.

I am sure glad now that I did not take his advice!

Back in 2005, I installed a special Belden 'bonded-pair' Cat5e cable and am very glad I did. At the time I was only looking to support Fast Ethernet (100 Mbps), but since then, I have converted to 1 Gbps Ethernet and suspect this high quality cable will easily support even higher speeds (especially considering that the 'run length' is way shorter than the maximum 100 meter / 328 feet).

Ethernet is full duplex, and Ethernet 'switches' allow for full speeds between different ports on the switch. Namely, a 16-port 1 Gbps switch allows for 32 Gbps of non-blocking bandwidth, and that is something that Wi-Fi simply can not do.

One room in a new home had two CATV jacks, but the structured wiring cabinet only had ONE run to that room. The installer accomplished this via a CATV splitter somewhere in the walls! He clearly did not understand 'structured wiring' (or was trying to hide a wiring mistake).

Every 'run' in 'structured wiring' home MUST be a 'home run'.

• telephone jack
• CATV
• wired LAN
• thermostat
• doorbell
• security camera
• Wi-Fi access point
• desks
• game console
• any other location you can think of

An alternative?: Consider adding strategic 'smurf cable' ENT (electrical non-metallic tubing conduit) runs to many locations.

So when you have spare CAT6a in every room, that allows you to make changes 'down the road' that you can't foresee today.

• Every room/desk 'phone location' got one Cat5e (four phone lines) and one spare Cat5e.
• Every room/desk 'Internet/LAN location' got two Cat5e (each connected to a different switch in the structured wiring cabinet - for redundancy).
• Every 'CATV location' got two RG6 and one spare Cat5e.
• Every 'thermostat location' got a spare Cat5e.
• The 'CATV demarc location' got one RG6 and one spare RG6.
• The 'phone demarc location' got one Cat5e and one spare Cat5e.
• The (potential) 'satellite dish demarc location' got two RG6.

1. I should have run spare Cat5e to: (a) doorbell locations, (b) anticipated security camera locations, (c) security alarm base station location, and (d) all potential Wi-Fi AP locations.
2. Run more spare CAT5e to ALL the utility demarc locations (where phone/CATV/etc enter the home) at the side of the house, because I have already repurposed all of the CAT5e there for other purposes (PoE security cams) and need more.
3. Plan on more electrical outlets in the structured wiring cabinet than you think you need, and place onto a dedicated electrical circuit. You don't want it on a shared bedroom circuit, overloading (hair dryer + something else), tripping, and taking down Internet for the entire house.
4. Plan on having 'expansion room' in the structured wiring cabinets for future changes. Over the years, I added (a) Internet to all TV locations (b) VoIP telephone, (c) six PoE security cameras, (d) etc.

I had initially planned on having only four powered devices (modem, router, and two 16-port switches), but over fifteen years, I have since added seven more powered devices into the cabinets. Managing the space for all of those power cords/bricks was a huge challenge. I actually needed to change the layout of both panels (years later) to make room.

Just put a dollar sign in front of the 'watts consumed' to obtain a 'minimum' estimate of the yearly cost in dollars.

Watts = Amps × Volts   (W=A×V)

Kill A Watt P3

Namely, the power adapter for my TP-Link AX80 says it can output 12V 3.3A (12×3.3=39.6 watts). But using a Kill-A-Watt measuring device, the router uses around 7 watts idle, and around 13 watts when Wi-Fi is actively being used.

Estimated $/Year = Watts/1000 × 11.408¢/100 × 24 × 365.25

Estimated $/Year = Watts × $1.00

Actual $/Year = Watts × $1 × corrective_factor

See the table right for more 'corrective factors' for various states.

MoCA adapter setup

Hitron HETM5 Adapters

WARNING: I have also seen disclosures stating that MoCA adapters should NOT be used in homes where the coax cable is already being used by satellite TV, or for AT&T services (as they already use MoCA internally for their own boxes). This need more research and verification (because different MoCA devices in the home should be able to just use different channels and easily coexist).

MOCA 2.5 Splitter

Splitters: All cable splitters everywhere in your network (both inside and outside the house) must support MoCA frequencies -- up to 1675 MHz. Example splitters (amazon.com) -- notice that the splitters are expressly labeled as supporting "MoCA 2.5". If your existing splitters do not say this, they should be replaced.

MOCA PoE Filter

PoE filter: There must be a MoCA PoE (point of entry) filter on the cable line feeding your entire house. Example filter (amazon.com). It is common to find an all-in-on 'grounding block' and 'MoCA filter' inside the cable demarc box. The filter prevents MoCA signals generated inside your house from feeding back into the cable network, and reaching your neighbors.

If your house has a powered amp and it has a "MoCA" logo on it, it almost certainly already has a PoE filter built-in. Just Google the model number of the amp to find a manual and confirm.

An example DOCSIS 3.0 MoCA PoE Filter (amazon.com) is seen upper right, which allows 5-1002 MHz to pass, but blocks MoCA frequencies 1125 MHz and above.

For example, see this blog post (gocoax.com) on preventing overlap that is happening today!

The bottom line: If you have a DOCSIS ISP and use MoCA, please do so understanding that MoCA is NOT a long-term solution to not having Cat5+ cable -- it is only a short-term workaround. With MoCA, you are sharing the RG6 cables with the ISP, and the ISP WILL eventually start using MoCA frequencies. An exception is if the RG6 cable is dedicated to MoCA (not shared with any DOCSIS ISP signals).

• The details of MoCA from the source (mocalliance.org)
• MoCA basics (drive.google.com) - SCTE presentation by PCT
• ma2500d (gocoax.com) - Network setup diagrams

NOTE: When you try to run an Internet downloaded BAT file, Windows will -- rightly so -- display a "Windows Protected your PC" message. To run the BAT file, click on the "More Info..." link, and then click on the newly exposed "Run anyway" button may need to scroll to find the button. You only need to do this once (Windows remembers the choice).

TIP: Always inspect BAT file source code before running any downloaded BAT file -- Right click on the filename and select "Edit in Notepad".

• Receive rate (Mbps): Wi-Fi Rx PHY.
• Transmit rate (Mbps): Wi-Fi Tx PHY.
• BSSID: MAC address of the AP connected to. Very helpful when you have multiple AP.
• Radio Type: displays 802.11n / 802.11ac / 802.11ax / etc.
• Band: 2.4 GHz, 5 GHz, 6 GHz, etc.
• Channel: Wi-Fi channel number (important to know because some perform better than others)

netsh wlan show interfaces

netsh interface ip show config

netsh wlan show all

Hitron CODA56 - DOCSIS 3.1 - 2.5 Gbps

"Certified to work with Xfinity, Charter Spectrum, Cox Gigablast, Cable One Sparklight, and Zito Media. Also works with Astound, Grande, RCN, and Wave" -- source.

When I called up my ISP and asked them about the Hitron CODA56 not being on their approved modems list the reply was 'Oh, that list is old -- if the CODA56 supports DOCSIS 3.1, it will work' -- and it did.

I had to replace all of my Surfboard modems because they had a buffering problem with Ring cameras, resulting in poor video quality. No other brand of modem I tested had this problem with Ring cameras. I learned my lesson.

Electrical plug

Standard 120/240V in the U.S. is AC (alternating current) at 60 Hz. Powerline networking works by injecting MHz (megahertz) frequencies into the same wiring (aka: intentional 'noise').

Powerline networking -- TP-Link AV2000

Why this adapter in particular? Because you might as well test the 'latest and greatest version' of powerline networking that has the best chance of success Just like you don't want to be testing Wi-Fi 4 today, you don't want to be testing a much older and slower version of powerline networking.

Over the years, powerline networking speeds have improved dramatically (like ×10) -- from AV200, AV500, AV600, AV1000, AV1200, and AV1300 to now AV2000 -- for the HomePlug AV2 (wikipedia.org) standard. Note that there is also a competing G.hn (wikipedia.org) PLC standard.

So why mention powerline if it is potentially 'slow': (1) because what is 'too slow' or acceptable depends upon your situation and (2) powerline is inexpensive and easy to test/try. So if you get the speeds you need remotely, even if slow -- job done.

• Do NOT plug PLC adapters into power strips -- instead, plug powerline adapters directly into a wall outlet. Why? Because many power strips also filter out 'noise'. But the PLC signal IS actually intentional high frequency noise, which is then blocked!
• Minimize the total distance / 'stops' over internal house electrical wiring. From (a) one powerline adapter, (b) through outlets, (c) to the circuit breaker panel, (d) traversing to a new circuit breaker, (e) through outlets, and finally to (f) the next powerline adapter. Reducing the number of 'stops' on the path will increase powerline networking speeds.
• Avoid outlets on AFCI circuit breakers -- some models can kill speeds (are are harmful to MHz frequencies), while other models are OK. Source (smallnetbuilder.com).

• 475 Mbps - 8 feet to 45 feet apart on the same extension cord
• 320 Mbps - same room different outlets (same circuit breaker)
• 120 Mbps - different rooms, across two circuit breakers (both same and different phases)
• 100 Mbps - to an outbuilding (70' electrical run), to an outlet right next to the sub-panel
• 30 Mbps - to an outbuilding (70' electrical run), to an outlet in the outbuilding

"Whereas HomePlug AV always transmits on the Line-Neutral pair, HomePlug AV2 can transmit on any two pairs formed by the Line, Neutral or Ground wires (Line-Neutral, Line-Ground or Neutral-Ground). This allows for significantly improved peak data rates and performance" - Source.

• How to troubleshoot your Powerline network (smallnetbuilder.com)
• Powerline networking FAQ (smallnetbuilder.com)

Back side of RJ14 telco jack

Look inside a wall jack. If you see 8 pins, that is likely Ethernet. But if you see only 2, 4, or 6 pins, that is very likely a phone jack. Look at the back side to confirm.

If you see four twisted pairs, but do not see lettering on the cable, or see "CAT 3", then you can still try to convert over to Ethernet. BUT, you may get 1 Gbps, but you could also get 100 Mbps, or even 10 Mbps. You just won't know until you try -- the shorter the cable run, the better the chances of 'out of spec' cable working.

'Home-run' cable installation

Home run: Every single phone location in the house and demarc location -- the phone signal from the telephone company has its own cable or 'run' to a single common utility location (see example right), hopefully inside the house.

How to convert 'Home Run' to Ethernet: Each CatX cable can be re-terminated for Ethernet, and directly used. You can pick and choose which phone jacks you want to convert, possibly leaving some phone service remaining.

What if all home runs terminate outside at the demarc box (instead of inside the house): Options: (A) Inside the house opposite the demarc box, open up the wall and pull the runs inside the house. (B) Terminate the demarc runs with RJ45 and plug runs into a PoE powered mini switch (and send PoE to power the switch over one of the runs) example device (ui.com). If there is not room in the demarc box for the switch, then push the phone demarc box the to side, and add your preferred enclosure over all the runs/switch. (C) same as above, but use an outdoor rated PoE powered switch outside the demarc box Example device (amazon.com)

Daisy-chained phone: There is ONE long CatX cable run (a) from the phone company wiring (often a 'demarc' box on the outside of the house) (b) 'in' to the first telephone location, (c) 'out' to the next location, (d) and so on until all locations have a cable. Like this:



When a phone jack is installed, the cable run is cut in half (so now you see two cables), and then several 'same colored' wires (like the blue pair for line 'one') are attached to the phone jack to: (a) activate the phone jack, and (b) continue the phone signal 'out' to the next phone location.

Select a 'break point' anywhere along the daisy chain (where one of the 'out's is disconnected). Everything before the break (one or more jacks) remain unmodified and connected to the phone system. But everything after the break is converted to Ethernet.

It is rare, but in some installations the cable at the last telephone location loops back to the demarc location -- and both ends of the cable loop are connected in the demarc location. This adds fault-tolerance into the wiring (the loop can be cut in half anywhere and all jacks remain active/working).

1. Add ONE Ethernet run: You can directly use any single run (jacks with the same numbers). If you need a longer run, add a small Ethernet patch cord between in/out jacks at the in-between locations. For example to create an Ethernet run all the way from the first location ('2' on first plate) to the last location ('4' on last plate), add a patch cord connecting ports at the two in-between locations.

2. Sodola PoE Extender + 1 Gbps Switch

   Add Ethernet to all / multiple locations: At one of the phone jack locations, add a 802.3at PoE switch and connect to the Ethernet wall jacks. Then, at phone jack locations 'down the line', add a $20 PoE extender (amazon.com) -- which: (a) is powered by PoE itself, (b) continues PoE downstream, (c) leave two Ethernet ports open for use at the phone location, (d) provides 1 Gbps Ethernet. Repeat as needed as this PoE extender can be daisy-chained.
   
   NOTES: (1) If you use PoE extenders to add Ethernet to each daisy-chained phone location, don't actually plug any PoE device in. The intention is that the entire PoE budget is there to power only the daisy-chained PoE extenders. (2) Of course, you can also use powered switches, and then a PoE switch and PoE extenders are not needed (for example, if you wanted 2.5 Gbps Ethernet, instead of the 1 Gbps PoE solution).

• Ubiquiti Flex Mini - "A compact, 5-port, Layer 2 switch powered by PoE or a 5V USB-C adapter."

If you get good Wi-Fi throughput standing right next to your router, but poor throughput far away from the router, then you simply have a 'distance' problem. Consider adding an access point [§18] into your network at that distant location, wired/Ethernet back to your main router.

In another case, I was getting great PHY speeds, but very slow Internet speeds. A bunch of speed tests eliminated Wi-Fi and my router as the cause. This suggested the problem was with the only remaining hardware -- the (cable company provided) modem. So I rebooted (only) the modem and instantly had my fast speeds back. Frustrating.

At one location, ISP download speeds were sometimes OK, and sometimes bad. Rebooting the cable modem caused it to acquire a 'random' set of bonded download channels from the CMTS. As one particular channel was having issues, this reboot caused the modem to randomly use/avoid the problematic channel.

Also, walk to your router and stand about five feet (line of sight) away from the router, cause some Internet activity, and then re-check PHY speed. On a 2×2 Wi-Fi 6 client, I would expect to see a very strong signal with a PHY speed of 1201 Mbps (or better). And for a Wi-Fi 5 client, expect a 866 Mbps PHY.

Newer client devices (in the Wi-Fi settings) may tell you the 'Frequency' (2.4 or 5 GHz) your device is connected to. If not, the PHY speed you see on your device should be a huge tip off as to which band (and channel width) you are connecting to. Look up the speed in the PHY tables [§F], which then reveals a ton of information about how you are connecting.

Split the Wi-Fi bands: Try turning off the 'Smart Connect' feature of the router (that tries to push the client device to the 'best' band). Or, for testing, go to the router configuration and confirm that the 2.4 GHz SSID and the 5 GHz SSID are uniquely named. If they are the same, append a "-5G" to the 5 GHz SSID name temporarily. When you see the SSID for each band, connect to the 5 GHz SSID. If PHY speed increases dramatically, you likely have a problem with your device connected to the (slower) 2.4 GHz SSID, instead of (much faster) 5 GHz SSID.

Wi-Fi Analyzer Access Points

Verify channel width: It is important to confirm that your 5 GHz SSID is operating at an '80 MHz' channel width. If you see '40 MHz' or '20 MHz' for your 5 GHz SSID (notice this for 'Goofy-5G' in example right?), go into your router configuration and fix the problem. The other possibility is that the router is only a dual-band Wi-Fi 4 (802.11n; not capable of 80 MHz channels) router and not actually a Wi-Fi 5 (802.11ac) router.

A: The most likely cause is that NOT all devices in your network are 1 Gbps capable. If there are any Fast Ethernet (100Mbps) devices between you and your ISP, that device becomes a 'choke point' that will very likely cause dropped packets and speed problems.

TIP: It is very common for ISP's to provision internet modems to 110% of the advertised speed. So if you sign up for 100 Mbps internet, your 100 Mbps network will not work, since the internet speed is more than likely actually 110 Mbps -- and any Fast Ethernet devices between you and the internet are a problem.

Another possibility is a bad Ethernet cable between two Gbps devices, causing that link to operate at the problematic 100 Mbps speed instead of the desired 1 Gbps speed. TIP: Many RJ45 jacks have tiny LED lights indicating speed.

A: Due to Wi-Fi protocol overhead, the expected throughput at the application level is around 60% to 80% of the physical (PHY) Wi-Fi speed. This is normal and sadly, the router industry has done a horrible job explaining this to the general public.

A: Blame router companies -- they love to advertise maximum speeds. Looking at the 5 GHz speed table far above, we can see that '1733' implies a 4×4 access point supporting 256-QAM. 650 is the PHY speed for a 2×2 device at 64-QAM. The conclusion is that your smartphone is a 2×2 MIMO device and that you are maybe 20 to 30 feet from your router. Expected application throughput will be around 70% of that, or 455 Mbps (±45 Mbps).

A: Maybe, but maybe not. Always try several different Internet speed test programs, like speedtest.xfinity.com, fast.com, or cfspeed.com. The very nature of the Internet is that everyone will not always be fast. I find that the Xfinity speed test gives the most reliable results, almost all of the time (and it had better, since Comcast is the largest broadband provider in the U.S.).

A: Fast Ethernet (100 Mbps) maxes out at a throughput of around 94.92 Mbps within applications. So the most likely cause is that the router is only 'Fast Ethernet' and you will need to upgrade to a Gigabit capable router (modem is likely 1Gbps ethernet, but router is only 100 Mbps, causing the bottleneck). OR, if your router is Gigabit, is there a (slow) Fast Ethernet switch somewhere in the network between you and your router? OR, double check the color of LED lights for RJ45 connections (LED color should indicate 1 Gbps and not 100Mbps). You may need to replace a bad ethernet cable (as Gigabit requires all eight wires to be good; 100Mbps only uses four of the eight wires).

A: This can happen when 'WMM' (Wi-Fi Multimedia) is turned off in the router configuration. To fix, turn 'WMM' back on. WMM is actually required for any speeds past 54 Mbps.

A: The most likely cause (if your router is configured for 80 MHz channels) is that your client device does NOT support 802.11ac. Instead, your client device is likely only 802.11n (no 256-QAM support), and supports 'dual-band' and is connecting to the 5 GHz band using the maximum 40 MHz channel width of 802.11n.

Visit devicespecifications.com or phonescoop.com to research versions of Wi-Fi supported by your smartphone (802.11n vs 802.11ac, etc).

A: Wi-Fi speeds decrease with distance from the router, and especially decrease through obstacles (walls, floors, etc). Your maximum speed will be when you are just feet from the router (and line-of-sight), and speeds will slowly decrease the farther away you move from the router. Sorry, but that is just how Wi-Fi signals work.

A: This can happen when a router is set to use channel 165. When channel 165 is selected, there are actually NO 40/80/160 channels available (so the router can only operate using 20 MHz channels). So even if the router is set to use 80 MHz channels, every Wi-Fi client connecting to channel 165 will only use 20 MHz channels. To fix, select a different channel.

A: Try a different channel on the router, or try updating Wi-Fi driver software on the client. The only time I have seen this is with an Intel AC-7260 laptop (channel 144 not supported) connecting to a Netgear R7800 router on DFS channel 140. The router transmitted to the laptop at 20 MHz speeds and the laptop transmitted to the router at 80 MHz speeds. Upgrading Wi-Fi drivers on the laptop resolved the problem.

A: First, can you connect wired/Ethernet to the Internet and confirm the problems go away (this confirms a wireless problem)? Try moving much closer to your wireless AP to maximize signal strength during the call. Try connecting to your router's other Wi-Fi band (2.4 GHz to 5 GHz, or vise-versa). Try changing channels on the router. As a last resort, try setting your router to use 20 MHz channels in 5 GHz and try different channels (this will greatly reduce your maximum Internet speed, but hopefully in return, you will gain an ultra-reliable connection for your video calls).

A: If you see the SmartByte application installed (to check, go into 'Control Panel / Uninstall a program', search on 'SmartByte', and if you get a hit, it is installed), disable the SmartByte service, as that Dell service is the likely cause. Google "beware of SmartByte" (google.com) for a discussion and instructions on how to disable/uninstall. This Dell service, designed to give priority to video streaming, actually causes slow Internet speeds. Anything designed to 'speed things up' that actually 'slows things down' is pure garbage. I have personally experienced this problem on multiple brand new Dell laptops. Absolutely crazy.

A: The most likely cause of the modem diagnostic page showing that all "Channel ID" have very low 'uncorrectable' errors, expect for one Channel ID with a sky high 'uncorrectable' count -- is is a bad RG6 cable or connector. Try using a different RG6 cable. See this paper (duckware.com) on cable modem connectivity problems.

A: Maybe. I experienced a similar issue first-hand with a Netgear R7800 sitting right next to a Netgear CM1000V2 cable modem. The Internet would sporadically drop. The cable modem was seeing a fair amount of "Uncorrectable Codewords", and T3 errors in the events logs. Moving the R7800 over three feet away from the cable modem seemed to reduce the problem. Your experience may be different, but in general, it is a good idea to keep RF devices away from other devices as much as possible.

A: Check to see if your router/mesh device has something called 802.11r "Fast Roaming" turned on. If so, turn off and see if that helps. Some older Wi-Fi client devices can't connect at all to networks with 802.11r enabled.

• TP-Link Routers (tp-link.com) - click on "Specifications" on top of product pages
• Netgear Routers (netgear.com) - on product page, click on "Specs", then "Technical Details"
• ASUS Routers (asus.com) - click on "Tech Specs" on top of product pages
• Linksys Routers (linksys.com) - find "Technical Specification" on product pages
• Eero Routers (eero.com) - expand 'Radio Frequency' section for MIMO specs
• Tenda Routers (tendaacn.com) - click on "Specification" on top of product pages
• WavLink Routers (wavlink.com) - click on "Specification" part of product pages
• Synology Routers (synology.com) - click on "Specs" section of product pages
• Google Routers (google.com) - click on "Tech Specs", expand 'Performance' section
• D-Link Routers (dlink.com) - click on "Specifications" section on product pages
• Ubiquiti Routers (ui.com) - click on "Technical Specifications" on product pages

• "256-QAM 5/6" for Wi-Fi 4/5
• "1024-QAM 5/6" for Wi-Fi 6/6E
• "4096-QAM 5/6" for Wi-Fi 7

• For the 2.4 GHz band, router companies almost always cite speeds for 40 MHz channel widths, even though most people will only be able to use 20 MHz channel widths.
• For the 5 GHz band and Wi-Fi 5, channel width is often 80 MHz or 160 MHz. If not disclosed, it must be deduced from all the other information provided.
• For the 5 GHz band and Wi-Fi 6, channel width for higher end routers will be 160 MHz, but will be 80 MHz for low end routers.
• For Wi-Fi 7, high end routers will cite speeds for 320 MHz (but lower end routers could cite for 80/160).

Note that two Mbps numbers added together means 'dual band'. If you saw three Mbps numbers added together, that is tri-band; and four Mbps numbers is quad-band.

• in the 802.11ax 40 MHz channel table, 1024-QAM 5/6 row, 1148 is value for 4×4 MIMO
• in the 802.11ax 160 MHz channel table, 1024-QAM 5/6 row, 4804 is the value 4×4 MIMO

In this case, the specification told us the MIMO levels for each band, but if not, we could have deduced it from the fact that Netgear told us this was a six-stream router. Looking up the disclosed Mbps values in the PHY tables spreadsheet (docs.google.com), the only MIMO combination that works and makes sense is that 5 GHz is 4×4 and that 2.4 GHz is 2×2.

• in the 802.11ax 80 MHz table, 2×2 MIMO is 1201 Mbps -- for 5 GHz band
• in the 802.11ax 40 MHz table, 2×2 MIMO is 574 Mbps -- for 2.4 GHz band

• in the 802.11ax 160 MHz table, 2×2 MIMO is 2402 Mbps -- for 6 GHz band
• in the 802.11ax 160 MHz table, 2×2 MIMO is 2402 Mbps -- for 5 GHz band
• in the 802.11ax 40 MHz table, 2×2 MIMO is 574 Mbps -- for 2.4 GHz band

TIP: Netgear 'Mode' means "channel width".

• 1733: Lookup 1733 in the PHY tables far above and you find it under the 80 MHz PHY table with 256-QAM 5/6 modulation and 4×4 MIMO.
  
  
• 800: Lookup 800 in the PHY tables far above and you find it under the 40 MHz PHY table with 256-QAM 5/6 modulation and 4×4 MIMO.
  
  
• 347: Lookup 347 in the PHY tables far above and you find it (346.6) under the 20 MHz PHY table with 256-QAM 3/4 modulation with 4×4 MIMO. Note that this is because 256-QAM 5/6 is not available in 20 MHz mode (for most commonly used MIMO configurations).

• 1300: Lookup 1300 in the PHY tables far above and you find it under the 80 MHz PHY table with 256-QAM 5/6 modulation and 3×3 MIMO.
  
  
• 600: Lookup 600 in the PHY tables far above and you find it under the 40 MHz PHY table with 256-QAM 5/6 modulation and 3×3 MIMO.
  
  
• 289: Lookup 289 in the PHY tables far above and you find it (288.8) under the 20 MHz PHY table with 256-QAM 5/6 modulation with 3×3 MIMO.

• 300: Lookup 300 in the PHY tables far above and you find it under the 40 MHz PHY table with 64-QAM 5/6 modulation and 2×2 MIMO.
  
  
• 145: Lookup 145 in the PHY tables far above and you find it under the 20 MHz PHY table with 64-QAM 5/6 modulation and 2×2 MIMO.
  
  
• 54: This is the exception. In Netgear routers on the 2.4 GHz band, this sets the router to 802.11g (54 Mbps) operation only.

TIP: Reboot all of your test equipment before running throughput tests. I have spent WAY too much time trying to track down the cause of a slow performance test (and NOT finding the problem), only to at the end, rebooting, and having the problem go away. Frustrating.

Xfinity speed test

ISP speed tests will only be 'reliable' at testing Wi-Fi throughput if the ISP speed is known to be faster than your expected Wi-Fi throughput.

TIP: But if ISP speed tests over Wi-Fi improve significantly as you move closer to the router, that is a classic sign that Wi-Fi is indeed the 'choke point', and limiting throughput.

But these disadvantages are a very small price to pay for the huge advantage and convenience of (1) not having to install any software elsewhere in the network being tested and (2) working independently of LAN Ethernet speed (not limited when LAN is only 1 Gbps). Besides, there is often just a single Wi-Fi hop to test as client devices often connect directly via Wi-Fi to the main router or AP, and client Tx speed is often (but not always) slower than Rx speed, so this often ends up testing the desired 'weakest' Tx link.

TIP: Validate your LAN speeds first. Run this speed test program between two computers on your LAN first, to confirm that both client+server computers, and your LAN, can handle full LAN speeds. Expect around 5.1% overhead for TCP over Ethernet. On a 1 Gbps LAN, expect measured throughput speeds to max out at around 949 Mbps. On a 2.5 Gbps LAN, expect the same 5.1% overhead and a maximum measured throughput speed around 2.37 Gbps.

USB-C 2.5 Gbps Ethernet

Inexpensive 2.5 Gbps Ethernet: You will need a 2.5 Gbps (or faster) Ethernet network to measure any Wi-Fi speeds past 1 Gbps (and up to 2.5 Gbps). The uni USB-C to Ethernet Adapter 2.5 Gbps (amazon.com) (seen right) is an inexpensive (around $27) way to add 2.5 Gbps Ethernet to computers with USB-C.

Do NOT buy the Anker brand of this adapter. I did and found that it is unable to connect when a laptop of plugged into AC power (and on battery, it only works to 1 Gbps). Crazy bug. The 'uni' works just fine for me. Both the Uni and Anker use a Realtek chipset. So make sure that your Realtek drivers are up-to-date. Compare to the latest version at Realtek USB FE / GBE / 2.5G / 5G Ethernet Family Controller Software (realtek.com). When I connected to a Windows 10 laptop, speed was bad and the driver was crazy old (from 2015). Problems were fixed after updating the driver (but not for Anker).

Windows: Run the "Task Manager" app, select 'Performance', select 'Wi-Fi'. The result is a graph of Wi-Fi performance. Optionally (and a little harder to use), right click on the graph, select "View network details", and the result is real-time (once/sec) information (example seen right).

TIP: The FastPing manual page shows how to use the built-in Windows+Linux 'ping' tool to manually perform very basic throughput testing, using large pings. Great for testing throughput to/from IoT devices with limited (72 Mbps) Wi-Fi speeds.

There is a very small 'turn-around' time in the router that is also (unavoidably) measured by FastPing. For slow connection speeds, this delay is inconsequential. For fast connection speeds, this delay dominates and makes the speed less accurate. For this reason, FastPing is great at comparing two Wi-Fi connections (fastest speed wins).

• Multiple computers on Wi-Fi: When running speed tests between two computers, one computer must be on Ethernet (with Wi-Fi off) and the second computer must be on Wi-Fi. If both computers are on Wi-Fi, you will not get accurate speed test results.
• Multiple-use Ethernet ports: Avoid using dual-functionality Ethernet Router ports for speeds tests. For example, a port labeled WAN/LAN. I have seen bad speed test results from a WAN/LAN port used in LAN mode. I assume because packets are being routed between ports in the OS, instead of being routed between ports in hardware (the switch)?
• Flow Controller: Some routers have a 'Flow Controller' which allows for a 'pause' frame to be sent out (with the goal of reducing/eliminating lost packets). The interesting impact of this is that it can restrict Wi-Fi speeds above 1 Gbps to the Router's WAN port speed of 1 Gbps. One tip-off is Wi-Fi speed results (using TxRate above) capped at 949 Mbps.
• Kicked off DFS channel: Your router is configured to use a 160 MHz DFS channel, but is currently using a non-DFS 80 MHz channel. Verify channel number and width before and after running throughput tests.
• Buffering: The amount of TCP/IP socket buffering in the speed test program (or not) will have a major impact on speed test results. Programs not written for 'high performance' in mind may have trouble accurately obtaining and measuring speeds above 1 Gbps.
• Power Plans: If using a laptop, test with both the laptop plugged into the power brick and not (on battery). You want to understand if 'on battery' has any 'slow down' issues.
• Slow client devices: Always test Wi-Fi speeds against multiple client devices, including workstation class computers. You always want to measure true Wi-Fi capabilities, and not end up measuring a client device limitation.
• Older Routers: Many older routers (even 'high-end' Wi-Fi 5) don't have the horsepower to fully max out Wi-Fi capabilities and match throughput results from Wi-Fi 6 routers in Wi-Fi 5 mode. Newer often is better.
• WAN port speed limit: Speeds tests can only run as fast as the slowest 'choke point', which can be the Ethernet ports. For example, Wi-Fi on the Netgear RAX50 can run much faster than 1 Gbps, but throughput to the WAN or LAN is limited to around 949 Mbps by the 1 Gbps Ethernet ports.
• Give beamforming time to work: After first connecting to Wi-Fi, don't instantly run a speedtest. Instead, give 'new' connections a little time to 'synchronize'.

KEY Wi-Fi concept: A device's Tx and Rx PHY speeds are independent (and are often different).

To the right is an unusual example of actual measured PHY speeds in real life between a router and a laptop computer. Notice that the laptop might report a 'good' 270 Mbps for the Link Speed (out of max possible of 300 Mbps), but that downloads from the Internet will only use a PHY speed of 216 Mbps! Admittedly, this example is unusual, as most often the (higher powered) router can transmit at a faster PHY to the PC than the PC can transmit to the router.

The best way to notice and see asymmetric PHY speeds is to place a client device 'at range' away from the AP/router being used. The closer a client device is to the AP/router, the less you will notice the asymmetry.

Asymmetric PHY (as seen at AP)

Most modern clients are capable of 80 MHz channel widths and 2×2 MIMO. If you are not seeing PHY speeds indicating that, then you have an issue to investigate.

A key Wi-Fi concept: Notice that ALL 802.11 a/g Wi-Fi devices operate at the SAME 12,000,000 symbols/sec (at the same 'metronome' frequency). It is only the 'Modulation' and 'Encoding' that changes and determines true Wi-Fi throughput. So an 802.11g device operating at a minimum PHY of 6 Mbps AND an 802.11g device operating at a maximum PHY of 54 Mbps are BOTH transmitting symbols at a rate of 12,000,000 per second. Using terminology from decades ago, this is like saying that the 'baud' rate of 802.11 a/g Wi-Fi is a fixed 12,000,000 symbols/sec.

The same 'concept' applies to all other versions of Wi-Fi as well, but with multiple guard interval options. 802.11 n/ac has either 13,000,000 symbols/sec (800ns long GI) or 14,444,444 symbols/sec (400ns short GI) for a 20 MHz channel.

The modulation level (QAM 16, 256, 1024, etc) is just the number of unique values that can be 'understood' per Wi-Fi symbol, and bits is the 'power of two' that represents that value. For example, 256-QAM can represent any one of 256 values, or 2⁸, values -- meaning that 256 is able to transmit 8 bits of information.

• mcsindex.com - an old resource, very recently redone and updated to include 802.11ax info
• Cisco's 802.11ac MCS rates (cisco.com) - 802.11ac MCS rates
• SemFio Networks (semfionetworks.com) - includes a discussion of the math behind the numbers
• wlanpros.com (wlanpros.com) - interesting as table also includes minimum SNR and RSSI values
• 802.11ac Missing MCS's (youtube.com) - why some encoding combinations are not valid
• Wi-Fi (802.11) PHY Data Rates (blogspot.com) - How data rates are calculated

✔ Most devices receiving a Wi-Fi signal only 'see' a signal strength of 'around' 0.001 mW (close to AP) to 0.0000001 mW (far away from AP).

First cut: Use scientific notation. 100 mW becomes 1E2, 0.001 mW becomes 1E-3 and 0.00001 mW becomes 1E-5. Well, we are on the right track because we don't have to count zeros, but 'E' notation is still awkward to use.

Second cut: Use only the exponent. Instead of 1E2, just say 2. Instead of 1E-5, just say -5. But we still need to account for the non-exponent (mantissa) part, so use logarithms. For example, log(100) is 2, log(0.00001) is -5,and log(0.00002) is -4.699. This is workable, but can we eliminate the decimal digit...

dBm solution: Multiply the log(mW) result (from step above) by 10 and round to a whole number (no remaining digits). The unit of the resulting number is dBm (decibel milliwatts; deci=tenth). The dBm scale is expressly based/referenced upon 1 mW (the 'zero' point). The (easy to use) result is the table seen upper right.

"dBm" (decibel milliwatts) still represents milliwatt values (in decibel units), but dBm is a MUCH easier way to represent "mW" (milliwatt) values that have 'too many zeros'.

dBm = 10×log(mW)

mW = 10(dBm/10)

· Multiplying mW by 10 equals adding 10 dB to dBm · Dividing mW by 10 equals subtracting 10 dB from dBm

We can actually 'deduce' this from the table above. How many 'times 2' steps are there in going from 1 to 1000? 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024? It turns out that 2¹⁰=1024, so there are (very close to) ten steps. And ten steps from 0 dBm to 30 dBm means the step size is 30/10 = 3 dB.

FYI: The precise value is 10×log(2) = 3.0102999566...

• dBm (wikipedia.org) - Wikipedia information on dBm

Do NOT extend Wi-Fi signals wirelessly. Instead, use a wired Access Point.

Seriously, because if you do extend Wi-Fi wirelessly, all that accomplishes is a 'very slow speed' at distance (that then also uses up a lot of TIME on the channel). Namely, after successfully extending Wi-Fi wirelessly, you are then left with the problem of slow Wi-Fi speeds at that extended range -- and then you are back to square one -- how are you then going to improve Wi-Fi speeds?

TIP: First confirm that your main router is placed properly [§P] (centrally) in your home.

KEY Wi-Fi concept: Do NOT extend Wi-Fi signals wirelessly. Instead, extend Wi-Fi by adding a wireless access point that is wired/Ethernet back to your main router.

60 AP's providing Wi-Fi for Cisco in San Francisco

By splitting the Wi-Fi band names, you are taking an automated decision (of which band to connect to) away from Wi-Fi devices and manually deciding which band to use. The assumption is that you have tested and know which band is 'best' (for you, at your location).

Think about it, if you could increase the transmit power in an AP by a thousand times, that certainly would improve 'AP to client' communication, but that power increase actually would do nothing to help 'client to AP' communication, right?

With an AP using a higher transmit power, the PHY speed (and range) from the 'AP to client' would be greatly improved. But the PHY speed (and range) from the 'client to AP' would remain unchanged (because the client Tx power level is unchanged). So 'at range', clients will see asymmetric PHY speeds [§E].

TIP: To lookup the FCC ID for your phone, use phonescoop.com to find the web page for your phone, and the FCC ID is listed near the bottom of the web page. Then Google search the FCC ID and the search result at fccid.io should be what you want (displays power levels at various frequencies).

The key for understanding this idealistic model is noticing that what impacts received signal strength (in both directions) is: (1) transmit power, (2) transmit antenna, (3) path loss, and (4) the receive antenna.

2.4 GHz example: The Netgear R7800 router has a transmit power in 2.4 GHz of 975 mW and an antenna gain of 0.21 dBi. Source (fcc.gov). The Ring Video Doorbell Pro has a transmit power in 2.4 GHz of 82mW and an antenna gain of 1.08 dBi. Source (fcc.gov). Since both antennas are used in both directions, that is a essentially a 'wash' for comparison purposes. What becomes important is that the client has a rather large dB disadvantage of 10.8 dB (10×log(975)-10×log(82)). And that means that the Ring cam only has 29% (1/sqrt(975/82)) of the range that the R7800 router has.

This is why a Ring cam displaying the strong 'RSSI' ('AP to cam' signal) as an indicator of the connection quality is NOT very helpful, as the critical path for the Ring cam is the much weaker 'cam to AP' signal strength (uploading videos).

R7800 to Galaxy S6 long range

5 GHz example: The Netgear R7800 router has a transmit power in the upper 5 GHz of 969 mW. Likewise, for the Ring Stick Up Cam wired, the transmit power is 48.5 mW. The cam therefore has a 13 dB disadvantage -- or 22% of the range of the R7800 router!

5 GHz smartphone example: A Samsung Galaxy S6 is very similar, and results using the MCS Spy tool (duckware.com) can be seen right, and confirm the very asymmetric PHY speeds (as 'router to client' power is much higher than 'client to router' power).

So on paper, the 2.4 GHz band has 'more range' than the 5 GHz band, and in real-world testing, that happens often, but not all of the time. It is not uncommon to see the 5 GHz band provide just as much range (and MUCH better throughput). You just need to test. It is all about the SINR that can actually be achieved at a particular location.

12 dB hit (6 dB DFS + 6 dB 5 GHz)

Example: The Netgear R7800 for DFS channels transmits with 243 mW. The Ring Stick Up Cam Wired for DFS channels uses 54 mW, a 6.5 dB disadvantage for the camera. So the camera ultimately limits range (not the AP).

Instead of thinking "How can I extend the range of my one router", the much better question is "How can I improve Wi-Fi signal strength and still maintain good bandwidth". The answer is: by installing another access point [§18] exactly where it is needed, wired/Ethernet to your main router.

Also, high-gain antennas are not without consequence. They work by altering the 'shape' of the signal. Namely, instead of sending the Wi-Fi signal out in all directions (think 'sphere'), a high-gain antenna 'flattens' the signal pattern, sending more of the signal out in one direction (eg: horizontally) and much less in the other direction (eg: vertically) -- think 'doughnut'. This change is likely OK for a single story house, but not for a multi-story house. There can be a 'dead zone' directly above/below the high-gain antenna.

It is not uncommon to find 9 dB or even 12 dB high-gain antennas on Amazon. However, I have no idea if they are quality antennas, or not.

NOTE: With Wi-Fi 6E [§11] routers and later routers, expect only 'built-in' antennas that can NOT be changed (done to prevent abuse in the 6 GHz band).

Assume you do install high-gain antennas. What happens? All you have accomplished is adding several client devices at range at very slow PHY speeds, causing them to use the bunch of TIME on the channel, potentially slowing everyone else (on the same channel) down.

Also, I can not stress enough the need to test actual throughput [§D] in both Wi-Fi bands. The conventional wisdom and 'on paper' calculations show that 2.4 GHz has 'better range' than 5 GHz, but in the real world, this is NOT always the case! It may be true, but it often may not be true. Actual SINR [§K] is far more important. I frequently see a big jump in performance switching to the 5 GHz band. The ultimate cause is 'noise floor' and interference differences. It does not matter if 2.4 GHz has a stronger signal strength if that also means a lower SINR!

At one test location the 2.4 GHz band had a noise floor of -87 dBm, whereas the 5 GHz band had a noise floor of -108 dBm -- a huge difference of 21 dB -- explaining why 5 GHz at this location performed WAY better than 2.4 GHz. You simply won't know until you test both bands.

Every house around you (likely) has a Wi-Fi router, and there are a very limited number of unique non-overlapping Wi-Fi channels. So you are definitely sharing Wi-Fi frequencies with some neighbors. But most neighbor Wi-Fi activity won't impact you due to the fact that Wi-Fi signals attenuate rather quickly. Your router often only sees neighbor Wi-Fi activity as a slightly elevated 'noise floor'.

KEY Wi-Fi concept: The 'quick' attenuation of Wi-Fi signals is what actually allows 'everyone everywhere' to successfully use Wi-Fi 'all at once'.

Analogy: A great way to visually 'see' and understand this is to consider ever increasing spheres. Imagine an antenna at the center of the sphere and the surface area of the sphere is the radio signal as it travels outwards (in all directions). The (fixed) power output of the antenna must be distributed across the entire surface area of the sphere. Seen right are three spheres of radius 1, 2, and 3 (so a doubling and tripling of distance/radius). The formula for sphere surface area is 4×PI×r². The critical term to focus on is r². And you can confirm with your eyes that the sphere of radius 3 has a surface area that is not just three times larger, but 3² (nine) times larger (than the sphere of radius 1).

TIP: You don't have to memorize the Inverse-square law formula. Instead, just remember this 'sphere' analogy and you can easily mentally derive the relationship between distance and signal strength.


Illustration of Inverse Square Law from Wikipedia.org

(new_dist/old_dist)2 = (new_pow/old_pow)-1

(new_dist/old_dist)2 = old_pow/new_pow

old_pow × old_dist2 = new_pow × new_dist2

TIP: The best way to use this final formula is to fill in the three terms that you do know, and then solve for the one remaining unknown term.

KEY Wi-Fi concept: The change in Wi-Fi signal strength (in mW) is inversely proportional to the square of the change in distance.

Unless you are working in a pure 'line of sight' environment, walls and other obstacles will have a far greater (negative) impact on signal strength than distance will.

BUT, if you have a Wi-Fi analyzer app on your smartphone, it is sure interesting to see this actually work in practice. Stand five feet from your router, cause internet activity, and then run the analyzer app and check the dBm value. Then exit all apps and double the distance from the router (try to remain 'line-of-sight') and repeat the process. At least in my testing of this, I do see a 6 dB drop in dBm every time I double my distance from the router.

A model of Wi-Fi Distance vs RSSI behavior (line-of-sight; NO obstacles)

Notice how the power level is adjusted by 6 dB many times before we even get to 40 feet away from the router. And then the next 6 dB adjustment doubles that distance. The 'sweet spot' for most Wi-Fi connections is between -40 dBm (pretty close to a router) and -65 dBm (any farther away and lower throughput may be very noticeable).

KEY Wi-Fi concept: Wi-Fi in the 2.4 GHz and 5 GHz bands (but not the 6 GHz band) requires you to be 'just a little closer' to your router in order to successfully connect with increased channel widths using maximum QAM modulation.

The easiest way to mitigate this reduced SNR is to always be close to an access point.

Client forcing 20 MHz channel

TIP: Alternatively, some client devices (eg: Windows) allow the '5 GHz channel width' to be specified/forced to 20 MHz (normally a client would just use the channel width of the access point). This has the huge advantage of allowing you select an 80 MHz channel on the router (so most clients get 'fast speed'), and then only setting 20 MHz channels for those few (far away) clients that need 'extra range'. See example (right) from Windows Control Panel / Device Manager / Network Adapters / select Wi-Fi adapter.

If your client device is able to see a weak router SSID in the Wi-Fi list, but is unable to connect to it, the router-to-client signal strength may be OK, but the client-to-router signal strength may be too weak.

• Power Spectral Density and Wi-Fi 6E (juniper.net)

SINR: When there is lots of interference (eg: ACI), the signal-to-interference-plus-noise ratio (wikipedia.org) (or SINR) becomes much more important than just SNR. A transmitted signal must be properly 'heard', and the noise floor and interference are both critical for determining how well that happens.

KEY Wi-Fi concept: The PHY speed (and throughput) you experience in Wi-Fi is determined not by RSSI, but by how far RSSI is above the 'noise floor' -- a value called SNR (signal to noise ratio).

I have seen the noise floor for a band vary by as much as 23 dB (-105 dBm to -82 dBm), and the only thing that changed is physical location (of my travel router; different State). That is rather interesting, because it implies that where you are located (actually how congested Wi-Fi is around you) can actually have a VERY measurable impact on the SNR (and Wi-Fi speeds) you experience.

Please note that the 'noise floor' is not a constant value, but is always fluctuating (and sometimes by a lot).

"Noise is defined as any signal other than the one being monitored" - Source (wikipedia.org)

Technically, there are ways to communicate at signal levels below the 'noise floor', like LoRa (wikipedia.com), but that is beyond the scope of this paper. Modern Wi-Fi relies upon a signal level well above the 'noise floor'.

RSSI stands for "Received Signal Strength Indicator". More Information (wikipedia.org). And while RSSI officially is a 'relative' number (to itself), with no (official) direct relationship to dBm, RSSI is often converted via formulas and displayed as just that (a negative number followed by "dBm").

Analogy: Talk normally in an empty room, and you can easily be heard (RSSI), because the 'noise floor' is so incredibly low (high SNR). But talk normally again (so RSSI signal level is the SAME) in a bar, and you won't be heard, because the 'noise floor' is so high (low SNR) relative to the signal level. The same thing applies to Wi-Fi. As long as the SNR for a Wi-Fi signal is 'good', that signal will be heard and understood.

The implication of this is that regardless of RSSI (even a poor RSSI), a high SNR at the same time means high throughput is very likely, but a low SNR means that high throughput is impossible.

I have seen discussions online state (but have not personally verified) that in industrial environments, large electrical motors running can cause the 'noise floor' to be so high (meaning SNR is always very low), that getting any Wi-Fi to work can be very challenging.

Because 5 GHz signals attenuate more through free space (and obstacles), that is providing a noise floor advantage for 5 GHz. I often see the 2.4 GHz noise floor at/around -86 dBm. Whereas for 5 GHz, the noise floor is often around -105 dBm.

★ The implication of this is that the 5 GHz band (even with 'technically' shorter range) may in fact provide much faster throughput then the 2.4 GHz band. And I say 'may' because I often find that the 5 GHz band is better/faster than the 2.4 GHz band, but there are exceptions.

When I travel, I run the Wi-Fi Analyzer on my smartphone to see how many access points my phone can see. I never saw a SSID with a RSSI in the mid -90's in the 2.4 GHz band, until one day (in the Florida Keys) I saw a RSSI of -95 (seen right). My take away from this is that the 'noise floor' at this location must have been VERY low in order for a signal at -95 dBm to not only be heard, but understood.

MacOS: An exception is that MacOS displays Noise dBm right next to Signal dBm. Very helpful. Use it.

TIP: What this means is that if a device is having trouble maintaining a Wi-Fi connection (and can't be moved closer to the router), and you would rather have a much slower PHY connection that stays up all of the time (than a faster connection to drops in and out) -- try reducing channel width (from 80 MHz to 40/20 MHz).

Now you know one key reason why many low-bandwidth IoT devices stuck to the 20 MHz channels of Wi-Fi 4 vs the 80 MHz channels of Wi-Fi 5 (they have no need for the higher throughput and would rather have increased range).

• 802.11ac Receiver Minimum Input Sensitivity Test (mathworks.com) -- lists IEEE table with sensitivity values
• 802.11ax receive sensitivity requirements (arubanetworks.com)
• IEEE 802.11-2012 Table that shows SNR requirements per modulation level (wirelesstrainingsolutions.com)
• IEEE 802.11 EVM specification (rfwireless-world.com)
• Signal-to-Noise Ratio (SNR) and Wireless Signal Strength (meraki.com)

This has been invaluable to analyze the Wi-Fi behavior of a 'locked down' devices (what channel width, Tx and Rx PHY speeds, etc the cam uses).

TIP: When analyzing a device (like a Ring cam), only have that one device connect to the router via Wi-Fi (so all Wi-Fi stats on one Wi-Fi band must be from the device being tested). And then on your PC, telnet to the router via Ethernet (or the other Wi-Fi band).

WARNING: Telnet is a text based protocol (not encrypted). So only use it on 'research' networks (not production networks) where you trust everyone currently connected to the network.

wifi0 is the 5 GHz band and wifi1 is the 2.4 GHz band or vice-versa, use iwconfig (described below) to confirm.

This is a GREAT way to independently measure both Rx PHY and Tx PHY, with no cooperation needed on the part of the device being measured! The MCS index reveals the (approximate) PHY speed used (don't know guard interval differences), and quickly tells you if there are symmetric or asymmetric PHY speeds. Seen right is an example where both Tx and Rx PHY are 'mostly' using MCS 7.

In another example, all MCS numbers were pulled into Excel and produced the chart below -- which clearly indicates that the cam is able to receive from the router much better (ave 35 Mbps) than the cam is able to transmit to the router (ave 16 Mbps).

And by only changing Wi-Fi channels, cam upload speeds (the majority of everything the cam does) improved significantly (now averages 27 Mbps):

The TxRate and RxRate displayed appear to be kilo (1024) based numbers instead of bps (1000) PHY based numbers. So multiply by 1024/1000 to correct back to 'bps'.

RSSI displayed under Atheros is actually SNR, which is a very important number to know.

In one dual-band router tested, ath0 was the 5 GHz band and ath1 was the 2.4 GHz band. Use iwconfig (described below) to confirm the setup for your router.

OpenWRT: iwinfo wlan0|wl0|ath0 assoclist: source1 (serverfault.com) source2 (openwrt.org)

This is incredibly useful to clearly 'see' the difference in transmit power (in dBm units) between the different bands/channels in 5 GHz (using DFS channels in 5 GHz have a 6 dB penalty). Also of note is that these power levels do NOT include antenna gain.

It becomes incredibly obvious after running this tool that not only are PHY speeds asymmetric, but that there is no single PHY speed in one direction. Rather, the PHY speed is constantly fluttering around. This is especially evident when the device being tested (eg: tablet) is moving around (with a person walking).

aid:1 rateset [ 1 2 5.5 6 9 11 12 18 24 36 48 54 ] MCS SET : [ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ] idle 10 seconds in network 183111 seconds state: AUTHENTICATED ASSOCIATED AUTHORIZED flags 0x1000e03a: WME N_CAP AMPDU HT caps 0x3c: GF SGI20 tx data pkts: 560610 tx data bytes: 80242252 tx ucast pkts: 277309 tx ucast bytes: 45807854 tx mcast/bcast pkts: 283301 tx mcast/bcast bytes: 34434398 tx failures: 246 rx data pkts: 217168 rx data bytes: 210097118 rx ucast pkts: 211051 rx ucast bytes: 209558247 rx mcast/bcast pkts: 6117 rx mcast/bcast bytes: 538871 rate of last tx pkt: 58500 kbps rate of last rx pkt: 117000 kbps rx decrypt succeeds: 1087298 rx decrypt failures: 0 tx data pkts retried: 5851 tx data pkts retry exhausted: 246 per antenna rssi of last rx data frame: -66 -57 0 0 per antenna average rssi of rx data frames: -64 -57 0 0 per antenna noise floor: -89 -92 0 0

qcsapi_sockrpc CMD wifi0 0

• get_tx_mcs
• get_rx_mcs
• get_tx_phy_rate
• get_rx_phy_rate
• get_noise
• get_snr
• get_rssi_dbm

iw dev DEVICE station dump